Staphylococcus Aureus

staphylococcus aureus
Abstract
This paper explores the study of an unknown bacterial culture. The bacterium were randomly
assigned in a double blinded fashion to alleviate scientific or experimental error in determining their
gram stain, morphology, arrangement, and scientific classification. There were eight unknown
bacterial cultures given, with the unknown bacterial culture being one of the eight bacterial cultures.
A myriad of tests and experiments were performed on the unknown bacteria in order to be able to
properly classify it. One of the first experiments that was performed was the gram stain. It was
determined to be gram positive. The arrangement of the unknown bacteria was also noted on the
gram positive slide. The slide showed grape like ... Show more content on Helpwriting.net ...
A urea hydrolysis test was performed. A nitrate reduction was performed. The bacterial unknown
was grown on Kigler 's iron agar media, MSA media, soy agar media, PEA agar media, EMB media,
and SIM medium media. A gram stain was performed. A methyl red test was performed. A Voges–
Proskauer test was performed. A citrate test was performed. A motility test was performed. A gelatin
hydrolysis test was performed. A liquid broth agar was cultured to determine if there was use of
oxygen.
Results
After the multitude of tests performed, it was determined that the bacterial unknown was
Staphylococcus aureus. The gram stain slide was positive. The morphology and arrangement was
grape like cocci clusters. On the glucose fermentation test the bacterial unknown tested positive for
acid and negative for gas. The oxidase test was negative. The bacterial unknown tested positive for
catalase. In the litmus milk medium a K or alkaline reaction was observed. It tested negative for
urea hydrolysis. The bacterial unknown tested positive for nitrite. On the Kigler 's iron agar media it
tested negative for gas, positive for glucose, positive for lactose, and negative for hydrogen sulfide.
On the SIM medium media it tested negative for indole, negative for hydrogen sulfide, and negative
for motility. The bacterial unknown tested negative for methyl red. It tested negative for Voges–
Proskauer. It tested negative for citrate. It tested
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Khokana Outbreak Paper
Barb Rahmlow
Dr. Angelo Kolokithas
Microbiology
June 25, 2015 Khokana Outbreak 2015: The Needle in the Haystack The first step to identifying the
unknown bacteria residing on the blood agar plate sent in from Khokana was to do a Gram stain on
it. This is an important first step because it dictates further testing that will be necessary to arrive at
a final conclusive result. Viewing the fixed and stained slide under the microscope revealed round
chains of bacteria in a purple color signaling Gram–positive streptococci. A catalase test was
performed with no bubbling present indicating a negative result. This further confirmed the shape
and arrangement seen under microscopy. With this mind, the coagulase test was not done, as it
would be of no use since that specifies for staphylococcus, specifically for Staphylococcus aureus.
For streptococcus, an examination of hemolysis was necessary at this point. Shifting attention back
to the original blood agar plate, gamma hemolysis was noted, thus narrowing the field down to two
choices left. The unknown bacteria was either Streptococcus bovis or Entercoccus faecalis. This also
means the Optochin and Bacitracin sensitivity tests would not be needed as those pinpoint alpha–
and ... Show more content on Helpwriting.net ...
faecalis has a low pathogenicity (scilo), it is a virulent, opportunistic pathogen to be reckoned with
and is thought of as a super–bug. This is not only due to its ability to resist a variety of antibiotics,
but also its ability to travel and employ biofilm formations. It can grow and adapt in many different
environments. It can thrive in a wide range of temperatures and has disregard whether salt or oxygen
are present, or whether the pH is basic or acidic. Its resilience on inanimate objects makes it a
perfect candidate for transmission to occur within the hospital environment from hand to instrument,
but it can also be spread via hand–to–hand contact and from food contamination (Public Health
Agency of

Bacteria Ecology Essay
Introduction– This lab experiment serves as a model for community succession using bacterial
colonies as the model. A bacterial colony grows from a single bacterium and is composed of
millions of cells. Each colony has distinctive colony morphology: size, shape, color, consistency,
and color. Community succession is a phenomenon observed in the organizational hierarchy of all
living organisms. Community succession is not limited to bacterial colonies, but spans the entire
community of life. As the community grows, it changes the environment it inhabits, and the
resulting community is different than at the start. As community succession occurs in bacterial
colonies pH, odor, color, and consistency changes take place. In this ... Show more content on
Helpwriting.net ...
Methods– We began the experiment by noting the characteristics of the different milk ages by smell,
color, and pH was measured using pH paper. Fresh milk smelled like milk, had a white color, and a
pH of 7. 24 hour old milk had a very slight sour smell to it, was still white colored with a pH of 7.
Four day old milk had a sour smell, was white with visible chunks, and had a pH of 6. Lastly, four
day old milk smelled like sour cream, was yellow colored with white chunks, and had a pH of 5.
Once the characteristics of the milk were noted we began to prepare the agar plates for the different
milk samples. For cold milk, one agar plate was labeled undiluted, and one plate was labeled "10–
1". 0.5 ml of milk was pipette onto the plate labeled undiluted. 0.1 ml of milk was then pipette onto
the plate labeled "10–1", and the pipette was discarded. Using an alcohol and flame sterilized bent
rod, the milk was distributed across the agar plates. The lid was never removed completely, just
lifted up enough to allow the rod to thoroughly spread the milk. For 24 hour milk, we prepared four
agar plates by labeling them undiluted, "10–1", "10–2", and "10–3". 1 ml of milk was pipette onto
the plate labeled undiluted. Then 0.1 ml milk was pipette onto the plate labeled "10–1". We
proceeded to pipette 0.1 ml of milk into the 9 ml water blank labeled "10–2". The pipette was then
discarded and

Correlation Between Gram Positive And Gram Negative...
Purpose: To understand the difference between Gram positive and Gram negative bacteria. We also
used this lab to examine our mixed culture, which had been Gram stained, under the microscope.
Theory and background
The bacterial cell wall is the outer layer of the cell that aids in structural support and protection from
the outside environment. Bacteria can be identified by the structure of their cell wall and classified
into two groups known to have different cell wall types. Two of these types are referred to as the
Gram positive and Gram negative cell wall.
Gram positive bacteria, or bacteria with Gram positive cell walls, are very thick due to the large
amounts of peptidoglycan it contains. Peptidoglycan makes up most of the cell wall and is made up
of long chains of glycan that are joined together by short peptide fragments (Chess and
Talaro,2015). The many layers of peptidoglycan the cell wall contains are what allow it to provide a
rigid structure and solid support for the cell. In fact, the many layers of peptidoglycan in the cell
wall can range anywhere from 50–80 nanometers thick (Todar, 2012). Although the peptidoglycan
takes up the bulk of the cell wall in Gram positive bacteria, there are also two other components that
play an important role for the cell wall that are either nearby or attached directly to the
peptidoglycan. Attached to the cell membrane, which lies directly below the cell wall, is a molecule
known as lipoteichoic acid. The second

Gram Stain: A Summary
Summary: Microbe 1D was received and a series of tests was done. A Gram Stain was done and the
sample was gram positive. A streak plate revealed that the microbe was circular, convex, yellow,
buttery and opaque. The next test was the oxidase test. The microbe was oxidase negative. The next
test performed was the catalase test. The microbe was catalase positive. The last test performed was
a MSA streak plate. The MSA plate turned yellow. This was the final indicator that the unknown
microbe 1D was Staphylococcus aureus.
Procedure 1 Gram Stain: Purpose: The Gram Stain reveals whether a microbe is either gram positive
or gram negative. It also reveals the shape and arrangement of the microbe (Harley, 2014). Of the
twelve possible microbes, ... Show more content on Helpwriting.net ...
The following catalase negative microbe was eliminated: Sarcina aurantiaca. The remaining catalase
positive microbes remained: Staphylococcus aureus and Staphylococcus epidermidis. The next test
performed was the MSA Streak Plate.
Error: A possible source of error for the catalase test is that the hydrogen peroxide is too old and
would result in a false negative for the catalase test because the peroxide would not react well with
the microbe. This could be prevented by making sure the hydrogen peroxide is not too old (Brady,
Personal Communications).
Procedure 5 MSA Streak Plate
Purpose: The MSA streak plate test is used to differentiate between different microbes by their
reaction on the specific media. The remaining microbes are Staphylococcus aureus and
Staphylococcus epidermidis. On the MSA plate, Staphylococcus aureus turns the MSA plate yellow.
Staphylococcus epidermidis turns the MSA plate a darker red (Harley, 2014).
Procedure: The MSA steak plate test was performed using the procedure on pages 186–187 and
some information on page 191 of Microbiology, Selected Labs (Harley,

Lab Report Unknown Bacteria Culture
A total of 13 tests were performed on the unknown bacteria culture #1. Two tests were inconclusive
and could not be used. The first test was simply the phenylethyl alcohol agar (PAA) to check for
contamination because of its selectivity towards gram–positive bacteria. The alcohol in the agar
penetrates the thin peptidoglycan wall of gram–negative bacteria, which results in a slowed and
stopped growth. The mannitol salts agar (MSA) is a differential test due to the mannitol sugar. It
also has high amounts of salt (7.5% NaCl). If the organism can ferment the sugar, and produce acid
as a result, the phenol red pH indicator dye will turn yellow due to the acidic environment. If no
change occurred, then it is a negative result meaning that the bacteria ... Show more content on
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Xylose was a sugar testing for fermentation for differentiation between bacteria. If the bacteria could
grow and ferment xylose, then it would change the phenol red pH indicator dye to yellow and
possibly black, being a positive result. The sulphur indole motility (SIM) medium contains peptone,
iron, and sodium thiosulfate. The first two abilities that are tested are the sulphur reduction and the
motility of the bacteria. If the bacteria can reduce sulphur, it will react with the iron present and turn
the agar black resulting in a positive reaction. The motility test is determined by any movement
away from the stab sight in the agar. The indole test is done lastly by adding the Kovac's reagent to
test for the presence of indole from hydrolysing tryptophan (Levell, 2007 SIM). Sulphur reduction,
any movement, and indole production are all positive results. The eosin methylene blue (EMB) agar
tests for lactose fermentation from gram–negative bacteria usually found in the gut. If it can ferment
lactose the colonies will change to a pink/purple colour for a positive result and occasionally green
if it is more aggressive (Kadam,

Staphylococcus Epidermidis Essay
After performed the experiment and recorded all the result, the unknown #9 was found to be
Staphylococcus epidermidis. At the first place when the bacteria were stained, the slide was
observed purple under the microscope, from that the bacterial could be identified as gram–positive.
When the bacterial was gram–positive, there were several of test that could be run. After gram stain,
the bacteria were examined by used blood agar. The result from blood plate was no color change to
the medium around the individual colonies, this consumed that the organism of this bacteria was
non–hemolytic. The third test which was catalase give the positive result, because there were some
bubbles appears when drop 30% H2O2 on the slide. The MSA plate gave the ... Show more content
on Helpwriting.net ...
(2) These include: HIV and AIDS patients, the elderly, children, people who are immune–
suppression therapy with hematopoietic system disease (malignancy) underwent courses of
chemotherapy and radiotherapy. Staphylococcus epidermidis is the form of the sale of the acute
bacterial endocarditis. The main reason–the colony in prosthetics and install the valves. Very rarely,
Staphylococcus epidermidis highlights natural valve. The pathological processes that occur on the
deformed structure. Complications – instability of blood, heart failure, the risk of thrombosis
embolism. In second place on prevalence parts of urogenital system. Mainly affects women. Female
urogenital system has many features; the background causes frequent infections. Clinical picture of
cystitis or pyelonephritis. Found in urine increased number of white blood cells. The patient
complained of fever, impaired urination, pain during urination, pain in the abdomen. For diagnosis
using microscopy and culture methods. Be patient translate biological (blood, urine, feces, pus
discharge,) drainage pipe and wash and research conducted. The preparation is then dyed by a
special technique called gram stain. Staphylococcus epidermidis is like a bunch of grapes. (1) To
determine what type of staph is necessary to investigate its proteins, enzymes. Staphylococcus
epidermidis is a coagulase and not cause

Unknown Bacteria
As the flowchart shows, a series of tests were conducted to identify the unknown bacterium #65.
Microscopic observation of the gram stain indicated a gram–positive coccus bacterium. S.
epidermidis was used as the gram–positive control while E. coli was used as the gram–negative
control. This observation led to the elimination of all gram negative and rod–shaped genera:
Enterobacter, Citrobacter, Klebsiella, Escherichia, Pseudomonas, Serratia, Alcaligenes, Neisseria,
Proteus, Salmonella, Shigella, Erwinia, Veillonella, Flavobacterium, Bacillus, Arthrobacter,
Lactobacillus, Listeria and Kurthia (2). By performing the catalase test, it was determined that the
bacterium was catalase negative and it did not produce bubbles. M. luteus and E. faecalis were used
as positive and negative controls, respectively. ... Show more content on Helpwriting.net ...
The unknown bacterium did not produce any spores as was evident by the endospore stain. B.
subtilis (positive controls) was capable of producing spores in the NSM agar plate while no spores
were formed by E. coli (negative control). The spore–former Sporosarcina was eliminated from the
list of the possible genera. In the blood agar test, it was determined that the bacterium was gamma–
hemolytic when it was compared to the gamma–hemolytic control S. epidermidis and beta–
hemolytic control S. aureus. Since most species of Streptococcus are either alpha or beta–hemolytic,
the negative result of the blood agar hemolysins led to the elimination of Streptococcus (8). These
tests narrowed the possible genus to

Bio Pre Lab Report
Bio Pre Proposal
I. OBJECTIVE: To have the ability to identify gram positive and gram negative cells and understand
how the staining affects them.
II. HYPOTHESIS: if a smear of both Escherichia coli and Staphylococcus epidermidis are stained,
then gram negative and gram positive stains should result respectively and be identifiable under the
microscope due to the structure of the cell walls.
III. PROCEDURE:
1. Obtain a blank, sterile microscope slide. Using an inoculating loop add one drop of distilled water
to the slide.
2. Using an inoculating loop add both Escherichia coli and Staphylococcus epidermidis to the slide
to create a smear.
3. Allow the slide to dry completely, once dry heat fix the slide by passing holding the corner and
passing the slide through a Bunsen burner flame, do this quickly as to not cause the bacteria to
unstick from the slide, but slow enough to kill the bacteria to allow for staining.
4. ... Show more content on Helpwriting.net ...
Apply Crystal Violet with a pipette until the smear is covered and allow to sit for one minute.
5. After one minute rinse the slide with distilled water with a pipette.
6. Apply Gram's Iodine with a pipette until the smear is covered and allow to sit for one minute.
7. After one minute rinse the slide with distilled water with a pipette.
8. Flood the smear with 95% ethanol with a pipette JUST until the purple color is removed,
remember the purple color will only be removed from the gram negative cells so once the ethanol
runs clear rinse the slide IMMEDIATELY with distilled water.
9. Apply Safranin with a pipette until the smear is covered and allow to sit for 90 seconds.
10. Rinse the slide with distilled water with a pipette.
11. Place the slide into a book of bibulous paper and allow to

The Advent of Penicillin Essay
The Advent of Penicillin
The advent of penicillin forever changed the world of medicine at its discovery with its ability to
treat diseases, deadly at the time, that are now considered commonplace and easily treatable.
Penicillin was one of the greatest discoveries of the twentieth century, as antibiotics are one of the
most highly prescribed drugs in the world today. Although its discovery is often described as
serendipitous, the process by which it was cultivated was quite meticulous, and continued attention
has been paid to penicillin's further development. It is because penicillin and its derivatives have
played such a vital role in everyday medicine that it is such an important topic. Penicillin works by
virtue of its ... Show more content on Helpwriting.net ...
During this time, however, Fleming did meet with Howard Florey, who would later take on a vital
role in the development of penicillin. By the mid 1930s, the advent of sulfa–drugs essentially ended
all of Fleming's research on penicillin. However, during this time period, Howard Florey had begun
research on lysozymes, and took special interest in antibiotics in 1938 after reading Fleming's
original paper. Ernst Chain, working in Florey's lab, carried out many of the initial experiments in
lab mice, all highly successful in treating infections of streptococcus bacterium. Human tests soon
thereafter, also proved penicillin to be highly effective, even in cases in which sulfa–drugs had
failed. However, production of the drug was still a problem, and trials could not be conducted on a
large scale. By this time it was 1941, and although penicillin's benefits had proven, culture mediums
were still only yielding one part–per–million penicillin. With Word War II raging, and resources
becoming scarce, Florey negotiated with the Rockefeller Foundation of the United States to move
himself and a colleague to the United States in order for him to continue his research. This project
would gain added momentum when the United States entered the war, with the development of
penicillin becoming a war project. Shortly thereafter, it was determined that Fleming's original

How Morganella Morganii Is A Gram Negative Bacillus With...
I. Introduction
Morganella morganii is a gram–negative bacillus with no special arrangement. It is the third member
of the tribe Proteeae. This bacterium was first discovered in the year 1906 by a British bacteriologist
by the name of He. De R. Morgan. In the late year of 1939, the bacterium was named Proteus
morganii, and again changed some years later due to findings that this bacterium did not obtain the
ability to ferment all carbohydrates like the genus Proteus was capable of doing. Instead, researchers
found the bacterium to have the capabilities of ferment only glucose and therefore its name had been
changed one final time to Morganella (its own genus) morganii. While testing M. morganii, findings
show that it has its own special characteristics that differ from the usual Proteea. M. morganii does
not swarm on a nutrient agar plate like the typical Proteus would. It also does not produce the black
precipitate found in Hydrogen Sulfide gas tests. M. morganii produces phenylalanine deaminase,
which is the enzyme that wipes out the amino group, resulting in a phenyl pyruvic acid. It is a
facultative anaerobe meaning that it is capable of producing energy in the form of ATP by aerobic
respiration if oxygen is present in its environment. If oxygen is not present in the environment, the
bacteria is fully capable of producing energy in anaerobic environments as well. Morganella
morganii can be found in the soil, water, and feces. The bacteria is a common resident to the

Vibrio Natriegen's Generation Time
Title: Vibrio natriegens's generation time and optimal growth environment using a Closed–Growth
System.
Abstract: The objective of this experiment is to find out what the optimal growth environment is for
V. natriegens out of three different environments. The first is a Brain Heart Infusion broth (BHI) that
contains 50 mM of NaCl. The second is BHI containing 250 mM of NaCl. The third is BHI
containing 1000 mM NaCl. In order to obtain this, a growth curve graph must be constructed for
each different environment, and the generation time of the bacteria in each environment must be
calculated. The optimal environment for V. natriegens was found to be the BHI with 250 mM of
NaCl.
Introduction: The type environment that bacteria live ... Show more content on Helpwriting.net ...
It is the y value posted in the upper right hand corner. The following data was obtained from the
"Closed–System Growth" experiment:
As shown in the figure above, it is evident that V.natriegens grew faster when the Brain Heart
Infusion (BHI) broth contained 250mM NaCl. The # of bacterial cells at each time point was
measured following the equation given in the "How to generate a bacterial growth curve"
supplemental material posted on D2L. (2) The data was then recorded in the table listed above. A
growth curve graph was constructed using the data above which illustrated the differences between
each of the different BHI mixtures. The graph was then used to determine the generation time of
V.natriegens for each different environmental condition. In order to calculate the generation time (g)
the mean growth rate (k) must be calculated. The formula to do this is posted in the supplemental
material "How to generate a bacterial growth curve" on D2L. The k value calculated for each
condition goes as follows:
At 50 mM NaCl k= 2.2 generations per hour
The generation time for each condition goes as follows:
At 50 mM NaCl g= .45 hours per generation
With all of these calculations the environment that is optimal for V. natriegens was determined.

Water Contaminants Lab Report
After isolating the DNA pellet and gram staining the sample, it could be concluded that the DNA
found in the water sample was gram–negative. This is because the crystal violet stain did not remain
on the sample and the sample showed red. Gram–negative means the sample has thin walls, making
it easier to break the wall and get access to the DNA. The sample was stratified squamous and had a
strep bacilli growth pattern. This is essential to a thorough lab analysis of water contaminants
because it helps identify the type(s) of bacteria found in the water sample based on the growth
pattern, if it is gram positive or negative, and what type of tissue the cell has. After testing for
contaminants in the water, the local sample tested present for radon only and the William's water
sample tested positive for Chromium, Copper, and nitrates. These series of tests were necessary to a
thorough lab analysis of water contaminants, as it revealed what contaminants were in the water.
Chemicals like Chromium and Copper do not have many adverse effects at low levels, but if the
levels increase health problems can occur. This is why it is so important to test water samples for
contaminants. The Agarose Gel Electrophoresis revealed the DNA was relatively small due to the
fact it moved nearly halfway through the Agarose Gel. ... Show more content on Helpwriting.net ...
Before this lab, I was aware that contaminates are present in nearly everything, but I did not realize
just how present they are. I was surprised to learn about the amount of different chemicals found in
water supplies due to things like waste dumps, power plants, and runoff. It brought into perspective
the importance of having clean water. One thing I was also previously unaware of was the dangers
of radon exposure there is in basements, which adds to the list of reasons I do not want to live in my
parent's

Danish Physician Hans Christian Gram Stain, Escherichia...
Gram Staining: Micrococcus leteus, Escherichia coli, and Unknown Colony
Ethan Hinkle
Microbiology Lab 3051, Section 001
Instructor: Harrison Taylor
February 9, 2015
This report represents my individual effort. I did not receive or offer aid to anyone when performing
this assignment, nor did I plagiarize any material. Signed:
__________________________________________________________
INTRODUCTION
In 1884, Danish Physician Hans Christian Gram was in the process of developing a staining
procedure that would potentially differentiate prokaryotic (mainly bacterial cells) and eukaryotic
nuclei in tissue samples. However, Gram was not effective in developing the differential tissue stain,
his derived work would serve as the most valuable differential stain in bacteriology, the Gram–stain
(1). Moreover, it soon became clear that most bacteria could be catorgorized into two major groups
based upon their response to the Gram–staining procedure. Gram–positive bacteria stained purple,
whereas Gram–negative bacteria stained a pink–red (2).
Complete structures of Gram–positive and Gram–negative cells were not differentiable until the
development of the transmission electron microscope. Gram–positive bacteria comprise of a
singular, 20–80nm thick homogenous layer of peptidoglycan just outside the plasma membrane. In
comparison, Gram–negative have two apparent layers: a 2–7nm thick peptidoglycan layer incased in
a 7–8nm thick outer membrane. The most distinct

Mannitol Salt Agar Lab Report
When isolating the types of bacterium that is gram–positive, motile, halophilic, mannitol fermenters
that grow in the presence and absence of oxygen you would use the mannitol salt agar (MSA),
mannitol fermentation, and semisolid stab tests. To isolate a halophilic bacterium, mannitol salt agar
(MSA) can be used as a test. For a mannitol salt agar (MSA) test, you would need a plate where the
agar is mannitol salt and 7.5% NaCl. The 7.5% NaCl mix with mannitol shows the selective and
differential part of the test because some bacterium is not able to tolerate the high level, but can be
mannitol fermenters. To isolate a mannitol fermentation that grows in the presence and absence of
oxygen, mannitol fermentation can be used as a test. For a

Gram Staining Lab Report
The result of this experiment was prevented growth of any microorganism in nutrient agar out of
aseptic technique and that what we expected and we achieved to our goal of this lab. Another section
of this lab, we using another technique known gram staining. Gram staining is a common technique
used to differentiate two large groups of bacteria based on their different cell wall constituents4.
This technique helps to identify among Gram positive and Gram negative groups by coloring these
cells pink or violet. Gram positive bacteria stain violet due to the presence of a thick layer of
peptidoglycan in their cell walls, which retains the crystal violet these cells are stained with.
Alternatively, Gram negative bacteria stain pink or red, which is attributed to ... Show more content
on Helpwriting.net ...
In this lab, we sued Sterile toothpicks, a gram positive bacterial sample growing in nutrient broth
(Staphylococcus aureus), a gram negative bacterial sample growing in nutrient broth (E. Coli), Gram
Stain sets, glass slides, Light Microscopes with immersion oil. The first stride was Resuspended the
culture tubes by tapping, then, making a (triple slide) on a glass slid. The triple sild was divided a
slide to three section, place a drop small loopful of Staphylococcus aureus on one end in the slid,
then, place drop of small loopful of the E. coli in the other end, after that, added a drop mix among
Staphylococcus aureus and E. coli in the center of slide. After completely dry slid, it should start the
Gram–Staining Protocol. the Gram–Staining Protocol was used four types of stains those are Crystal
violet, Iodine, decolorize, and safranin, each of stain was stayed about 60S and the rinsed with
water. Finally, drying the slide by pressing the slid among the pages of the Bibulous table and put
the slide under the

The Laboratory Without Contamination Is Essential For The...
Introduction The ability to cultivate and identify organisms of interest in the laboratory without
contamination is essential for the study and classifications of many life forms. Different techniques
were used to differentiate the organisms. This process of transferring a microbe from one medium to
the next is called inoculating. The organism chosen in class will be used to construct further testing.
The purpose of this lab experiment was to find the identity of the unknown bacterial culture and use
all the methods and the assessments that were introduced in the class. By doing that we had to use
different techniques that guide us to find the right bacterium. A flowchart was given for the
unknown to help us find the right bacterium that ... Show more content on Helpwriting.net ...
After a couple days of incubation, the first test conducted for analysis was a gram stain. The gram
stain is used to determine the cell shape and color of the bacteria cell. It can also determine whether
the bacterium is positive or negative. If it is a positive bacterium, it will look purple when viewed
under a microscope. If it is a negative bacterium, it will look pink. The rod shape is usually long in a
cluster chain. The cocci shape is a small circle or a cluster of grapes. The next test that was
conducted was the KOH test. A large inoculate of the organism was placed in the center of a slide
and a drop of KOH in a corner. The two were carefully mixed together by dragging the KOH into
the organism. This step was done to determine whether the test was gram–positive or gram–
negative. KOH lyses the gram negative cells and results in a sticky and stringy substance while the
gram– positive remain watery in appearance. Once the KOH test was complete the SIM medium test
was conducted, this test was done to determine three separate tests in one test tube. We are looking
for the sulfur reduction, indole production, and motility of the organism. First, a SIM media tube is
prepared, and then label the SIM tube with your initials and the bacteria you're using. Next, use a
needle to pick an isolated colony from the plate. Then, inoculate the tube by making a single straight
stab down the middle

The Uses Of Differential Stain
Erica Stevens June 2, 2015 Gram Stain Laboratory Report
Purpose:
To understand how the use of differential stains can help us identify cell morphology. Also to
identify the presence of two different bacteria in our mixed sample by identifying differences in
color, shape and grouping of eubacteria.
Theory and Background:
Gram stain is the most important and "commonly used differential stain in microbiology" (1).
Developed by Hans Christian Gram in 1884, while searching for a way to visualize bacteria in lung
tissue of people who had died from pneumonia. Gram used crystal violet as the primary stain, iodine
as the mordant followed by treatment with ethanol as a ... Show more content on Helpwriting.net ...
The cell membrane is a selectively permeable barrier composed of a phospholipid bilayer and
proteins. This layer of the cellular envelope, protects the cell from bursting under external osmotic
pressure and for communication between cells. The cell wall is found on the outer surface of the
cellular envelope, and it is here that the composition of the cell differs (4). In gram–positive cells,
the cell membrane is separated from the cell wall by a thin periplasmic space. The periplasmic space
is an area for storage of enzymes secreted by the cell membrane and synthesis of peptidoglycan (3).
The cell wall is composed of peptidoglycans; many long chains of glycans linked together by
peptides creating a permeable mesh–like surface. In gram–positive cells the layers of peptidoglycans
is very thick (20–80nm) and it protects the cell from bursting from internal pressure (3,4). The cell
wall also contains polysaccharides (teichoic acid and lipoteichoic acid) that are embedded in the
peptidoglycan structure. These structures assist in maintenance of the cell wall, cell division and
pathogenic functions of the cell (3). Gram–negative cells have a larger periplasmic space that
separates the cell membrane from the cell wall. This periplasmic membrane is the site for metabolic
reactions (3). The cell wall in gram–negative

Bacterial Infection Report
The CSF cell count results presented correlate with bacterial infection. The high presence of WBCs
indicates a possible infection while the high percentage of polymorphonuclear cells indicates a
possible bacterial infection. The gram stained CSF resulted in gram–negative coccobacilli,
sometimes found in pairs. A positive aerobic blood culture also yielded the same gram stain result.
The CSF and positive aerobic blood culture were both cultured on Blood Agar, Chocolate Agar, and
MacConkey Agar. Both yielded growth of large, smooth, round, opaque grey–yellow colonies on
Chocolate agar but no growth was found on the Blood agar or MacConkey. This suggested that the
organism was fastidious meaning they require specific growth factors. The colonies were both
catalase and oxidase positive. The organism was identified as H. influenzae using the API NH
identification system. The CBC also presented an abnormally elevated WBC count with a high
neutrophil count. 25% of the neutrophil count consisted of Bands indicating a left shift. This means
that the bone marrow is releasing a large amount of immature ... Show more content on
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They are facultative anaerobes that grow best between 35–37C with 5% CO2. It is a fastidious
species requiring hemin, or X factor, and NADV factor for growth. Both of these factors are
available on Chocolate agar but not Blood, therefore assisting in the identification process. The
isolates are catalase and oxidase positive. H. influenzae is a pathogen that typically colonizes the
nose and throat, and is spread via person to person contact or respiratory droplets. Severe infections,
such as this case, may result in meningitis and typically affects children. Vaccines are available but
no information regarding that for this patient was available. The patient was transported to a larger
healthcare facility that specialized in cancer care to treat the

Gram Staining Essay
Introduction
This report discusses the technique of Gram Staining in order to characterize bacteria. Gram–
staining is a process in which the cells are immersed in crystal violet, iodine, ethanol, and safranin.
Based on bacteria's cell wall, most common bacteria are either Gram–positive or Gram–negative.
The Gram–positive cell wall are composed of multiple layers of peptidoglycan layers, whereas the
Gram–negative cell wall has one layer of peptidoglycan. Through the technique of Gram–staining,
the Gram–positive cells will turn purple do to the cells multiple layers of peptidoglycan.
Materials and Methods
The area being used underwent an aseptic technique to ensure the culture would not be
contaminated. The surface being used was wiped with alcohol and the lab member's hands were
washed. All non–flammable instruments were flamed. Two slides were then sterilized by wetting the
slide and then drying it.
Before preparing the Gram–staining, the technique of making a bacterial slide with heat fixation was
practiced. On one slide, a small drop of water was placed. Using a sterile inoculating loop, cell
material from a slant stock cultural was placed into the water droplet and mixed. The slide was then
left to air dry. Once the slide was dry, the slide was picked up by a non–flammable tong and ... Show
more content on Helpwriting.net ...
A drop of water was added to two slides, cleaned using the aseptic technique, by an inoculated loop.
The inoculated loop was sterilized, by placing the loop over the gas flame, and then placed into a
test tube containing Escherichia coli. The Gram–negative was then transferred to the drop of water
on one of the slides. The same method was used with Gram–positive Staphylococcus epidermidis,
transferring the cell material to the other drop of water. The two slides were then left to air dry.
Then, each slide was passed through the cool part of the gas flame three times as previously

Linear Synthesis Essay
On the first day of testing, a gram stain test, a KOH test, a catalase test, and an oxidase test were
completed. The gram stain test indicated that the unknown species is a gram positive rod, and the
bacteria showed no strings during the KOH test confirming that the species is gram positive. From
these two tests, the unknown was concluded to be in the family Bacillicae. The bacteria remained
yellow on the cotton swab even after the oxidase reagent was dropped onto the swab showing that
the bacteria is oxidase negative. For the second day of testing, the bacteria were inoculated on an
SBA plate, and the analysis of this plate was difficult. The result of the SBA plate was difficult to
discern, and it was unclear if the bacteria completed beta hemolysis or alpha hemolysis. Therefore,
an additional SBA test needed to be completed, and with this second test it was more obvious that
the SBA plate underwent alpha hemolysis. The SBA result showing negative beta hemolysis, along
with the negative result from the oxidase test, indicated that Bacillus cereus was not the identity of
the unknown. At the same time that the SBA hemolysis test was undergone, the inoculation of an
MSA plate at 37 degrees for 24 hours was also completed. There was yellow growth on the MSA
plate indicating that it could grow at 7.5% NaCl and ferment mannitol.

Gram, Gram And C. Gram
Gram's Stain was discovered in 1882, but published in 1884 by a Danish Bacteriologist Doctor by
the name of Hans Christian Gram. Gram stumbled upon this method while he was examining some
lung tissue from patients that had died of pneumonia. While examining this lung tissue Gram
discovered that certain stains were more favorable and retained by the bacterial cells. It was only a
few years later that Gram produced a staining procedure that he divided into two groups. The two
groups divided almost all bacteria into what he called Gram positive (purple) and Gram negative
(pink).
The Gram's staining procedure is still used today and is the method that forms the basis for
identifying bacteria. In order to perform this procedure, you will need a Bunsen Burner or a Tirrill
burner, alcohol– cleaned microscope slide, and water. You will also need The following reagents:
Crystal violet, Gram's iodine solution, 95% alcohol, and safranin. These stain reagents are important
because they are used to determine the Gram reaction for microorganisms' identification. Crystal
violet will stain the bacterial cell, and Iodine will bind the stain. The alcohol differentiates bacteria
retaining or not the crystal violet within the cell wall, and the safranin will be used as a counterstain
to stain the bacteria. You are now ready to start you process.
First you will need to light your burner to the hottest part of the flame before starting your gram
stain. After the burner is lit you will move to

Lab : Differential Staining- Visalization Of Bacterials...
Lab Title: Differential Staining– Visalization of Bacterials Cell Strutures Lab
The Aim of the lab: the purpose of the lab was for students to be able to differential between
endospore and vegetative cells by looking at their cell sturtures.
Materials:
Glass microcope slides
Bursen burner
Inoculating loop
Sharpie pen
Sterile Water
Beaker with boiling water
Malachite green ( primary stain).
Safranin (counterstain)
Bibulous paper
Method:
Prepare smear as directed by professor during the first few weeks of class. Make sure to heat fix the
smear to prevent it from been wash out during the experiement.
Put alittle drops of Malachite green while while the slide is seating face up on a boiling beaker for
5minutes.
Rinse the silent gently with distilled water to get rid of the stain and make sure to place the slide
over a staining container to prevent containmation of other lab equipments.
Put few drops of safranin on the slide, let it sit for about two minutes.
Rinse gently with distrilled water and remove any let over water.
Blot the slide dry and allow it to air dry
Use the microcope to examine the slide under a 100x oil immersion lens.
Starch and write down any specific details of specific cells
Dispose the slide in the appropriate waste container
Results: were starch and given to Professor Nathan in lab
Disscusion
▪ The lab was done to visualize the cell structure of the endospore. The endospore is used to
determine resistance spore of

Lab Report Essay
As described in method, two test were conducted to determine the morphology of the unknown.
Morphology of colonies in the growth was viewed based on fluorescent pigmentation of the
colonies. It was observed that the colonies had yellow pigment through naked eyes. To observe the
shape of the cell, cell was simple stain with methylene blue; which gave its structure blue color so it
can be observed under a microscope. It was concluded that the cell had rod shape. The data can be
seen in table 1, which represent morphology characteristics of the unknown. The structure of the cell
wall of the unknown was determined by observing the Gram test. For this test Gram stain yielded
pink coloration of bacteria, which states that the cell wall structure ... Show more content on
Helpwriting.net ...
Anaerobic jar contain anaerobic pack, which converts oxygen into water, creating anaerobic
environment. This does not allow bacteria who are unable to carry cellular respiration in absence of
oxygen to survive. The media that was placed in this anaerobic jar had no growth compare to the
ones that were placed in the aerobic environment. The tube showed cloudiness only at the top,
showing that it is a strict aerobe, color change to pink was detected. Although both of these test
show that the microorganism is a strict aerobe, oxidase test shows that the microorganism doesn't
produce cytochrome c oxidase enzyme, which is part of electron transport chain in cellular
respiration cycle. When the oxidase reagent was added to the unknown, no change color to purple
was observed, concluding that it doesn't produce cytochrome c oxidase. This doesn't contradict
result for strict aerobe, it just means that the unknown doesn't uses this type of oxidase for electron
transport chain. Bacteria that is oxidase–negative can be strict aerobes that uses oxidase other than
cytochrome c oxidase in electron transport chain. Observations from these test can be seen in table 5
that has material on characteristics of unknown which are related to the gas requirement of the

Gram Staining Lab Report
This week in Lab 3 we will be discussing and practicing simple and gram stains. Staining is the
process of making bacteria visible to isolate and experiment with. Staining helps to show the
bacteria in a color so it is no longer clear by increasing the contrast of the specific organism.
Staining is used in the medical field not just to look at bacteria and cultures but also for diagnostic
purposes. It can be used to highlight certain tissues and even specific parts within a tissue. There are
many different types of staining, including: Acid fast staining ( Ziehl – Neelson Technique),
Acridine orange stain, Auramine – Rhodamine technique, Calcofluor white stain, Capsule stain,
Cytoplasmic inclusion stain, Endospore stain, Giemsa stain, Flagilla ... Show more content on
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The smear concentration will directly affect the gram results by making a false positive or false
negative gram positive stain. Take the slide smears and put them in crystal violet solution for one
minute. Rinse all of the stain off with water. After all the water has been removed from the slide,
place it in the mordant which is Grams iodine solution. A mordant is an inorganic oxide that
chemically reacts with the dye and affixes to the cell. Rinse the solution off with water the same way
we did before and then place the slide in a decolorizing agent for 10–12 seconds. As not to wait for a
long time, rinse this off with water as well. Waiting to wash the decolorizing solution off will clear
all the dye of off the previously dyed cells. Put the slide in the counter stain safranin for one minute
and rinse with water. Place the slide on bibulous paper and wipe an access water of the slide being
careful not to disrupt the bacterial culture. Now that the slide is done, put it under the microscope
with an oil immersion to view under 100x magnification. Gram positive bacteria is blue or purple
and gram negative bacteria is red or

Essay about A Study on A. Nigra Seeds for Pharmaceutical...
Introduction Usage of natural antioxidants from plants and the other natural sources has been among
the most important ingredients in food and pharmaceutical industries. Having the ability to defend
against the reactive oxygen stress (ROS),Natural antioxidants can protect the human heath from a
lot of diseaseses, they are Generally Recognized As Safe (GRAS) and the have less toxicity in
industrial products compared to the artificial synthetic ones. Zingiberaceae is a family in the plant
kingdom that has been highly investigated due to its versatile nature and high medicinal impact. The
largest genus of Zingiberaceae family is Alpinia. In this paper , the antibacterial efficacy of hexane,
ethyl acetate and methanol isolated from Alpinia ... Show more content on Helpwriting.net ...
The samples were then dried properly to remove the trace of remaining solvent. The extracts were
subjected for vacuum drying in rotary evaporator. The free radical scavenging activity of seed
extracts of A. nigra were determined using DPPH whereby solution of DPPH in 99.99% ethanol was
prepared and was mixed with ethanolic solutions of n–hexane, ethyl acetate and methanol extracts
from A. nigra seeds at determined concentrations. The mixture was shaken and incubated. Butylated
hydroxyl toluene (BHT) as positive reference ethanol as negative reference were used. The
absorbance was measured using multimode microplate reader. Each sample extract were mixed with
dry KBr powders and their absorption spectra were obtained with a Perkin–Elmer FTIR
spectrophotometer. The 1H spectra were recorded on a Varian 400 MHz FTNMR. Each extract
sample were dissolved in CDCl3 , and the solvent signal was used for spectral calibration. Total
soluble phenolic compound content from three different dilutions of A. nigra seed extracts were
estimated according to the Folin–Ciocalteu colorimetric assay, using gallic acid as standard and the
absorbance was finally measured. To generate the standard curve, different concentrations of gallic
acid were used. Quantification of totall soluble phenolics in each extracts was determined from the
gallic acid standard curve. The antibacterial activities of all the extracts were tested against
Staphylococcus aureus

Ofloxain are Wide-Spectrum Quinolones and CEF Against...
The objective of the current study was to develop and validate a simple, accurate, precise and
selective stability–indicating gradient reverse phase high performance liquid chromatographic
method for simultaneous estimation of Ofloxacin (OFL) and Cefixime (CEF) in pharmaceutical
formulation in presence of degradation products. The chromatographic separation of Ofloxacin and
Cefixime was achieved on Shimadzu LC–20AT series HPLC having C18–ODS bonded column (250
×4.6 mm, 40 °C, 10 μL) using UV/Visible detector at 276 nm. The optimized mobile phase was
consisted of a methanol: phosphate buffer (50:50) at a flow rate of 1.0 ml/min. The retention times
were 4.799 and 1.602 min for Ofloxacin and Cefixime respectively. The proposed method provided
linear responses within the concentration ranges 5–25 µg/ml for Ofloxacin and Cefixime both. The
limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.0259, 0.078
µg/ml and 0.0206, 0.062 µg/ml for Ofloxacin and Cefixime F respectively. The developed method
was validated as per ICH guidelines with respect to specificity, linearity, accuracy, precision,
robustness and ruggedness. The studies data revealed that developed method was convenient, fairly
reliable, sensitive, less expensive and reproducible. Keywords RP–HPLC, Stability–indicating
assay, Ofloxacin, Cefixime, Forced degradation. Introduction Ofloxacin are wide spectrum
quinolones and CEF is a third–generation cephalosporin with a

Algebraic Structure Of The Honeycomb Hexagonal Topology...
Finite Element Analysis of Out–of–plane Compressive Properties of a Honeycomb Structures with
Hexagonal Topology Fabricated by the Kirigami Techenique
Belloufi Abderrahim , Mustapha Bouakba*, Mourad Boukhatem, Brahim Issasfa,
Département de Génie Mécanique, Faculté des Sciences Appliquées Université Kasdi Merbah
Ouargla, 30000 Algérie
*Corresponding author: Email: bouakba.mu@gamil.com
Abstract
This work illustrates the manufacturing of the honeycomb hexagonal topology structures by the
kirigami technical, and the compressive testing of this specimen. The cellular configuration is
simulated using a series of finite element models representing fullscale. The models are
benchmarked against experimental results from pure compression tests. Finite element models of the
honeycomb assemblies under compressive loading have been developed using nonlinear shell
elements from an ANSYS code. Good agreement is observed between numerical simulations and the
experimental results.
Keywords: FEA, Honeycombs, cellular, flatwise; Hexagonal topology
1. INTRODUCTION Honeycomb out–of–plane compressive properties are of interest for many
researchers because they are important for the mechanical performance of sandwich panels, such as
local compression and impact resistance. Bouakba et al (2012). Proposed a novel type Voronoi–
lattice and study this honeycomb by FEA on in–plane mechanical properties using the ANSYS code.
Many researchers have used FEA (e.g. numerical approaches) to better

Gram Positive Bacteria And Gram Negative Bacteria
Bacteria can be divided into two types of species, gram positive bacteria and gram negative bacteria.
To determine whether a certain type of bacteria was classified tests were conducted by Hans
Christian Gram; who discovered the differences within the cell walls of the bacteria. Gram positive
bacteria have a thick wall which consists of the protein peptidoglycan. This is opposite to gram
negative bacteria which has a thin cell wall, which fold over each other (Wells, 2017). They retain a
much thinner peptidoglycan wall between two membranes. The membrane surrounding the
cytoplasm and the outer membrane. (Wikipedia, 2017). Both gram positive and gram negative
bacteria both stain, gram positive retains violet dye. Gram positive bacteria don't retain the dye and
turn red or pink (Diffen, 2017). Due the difference in cell wall thickness gram negative bacteria is
harder to inhibit, compared to gram positive bacteria.
Two types of bacteria will be tested throughout this investigation, Serratia Marcescens and
Staphylococcus Epidermidis. Serratia Marcescens are gram negative bacteria, which can be found
on any surface. They mainly occur in water, soil, or and within animals located in their digestive
tract (Antonette B Climaco, 2017 ). They are stained red which can often be mistaken with blood
drops. This bacteria can affect the macrophages within the human body, this affects the immune
system and the destruction of foreign pathogenic cells within the body. Staphylococcus

Comparing The Cellular Morphology Of Table 2
Comparing the cellular morphology of table 2 to their respective pure culture in table 3. B. cereus
presented with a white colony, round colony morphology, smooth margins and flat elevation in both
pure culture and isolated culture; E. coli presented with a Yellow colony, round colony morphology,
smooth margins, and flat elevation; S. aureus presented with a White colony; round colony
morphology, smooth margins, and raised elevation.
In comparison of the cellular morphology of each bacterium in the mixture (table 2) to their
respective pure culture (table 3) showed that Bacillus cereus, Escherichia coli, and Staphylococcus
aureus are present in the mixed culture as their respective cellular morphology was the same as
compared to the pure ... Show more content on Helpwriting.net ...
However, additional tests can be performed to further differentiate the three bacteria from one
another. One example is the BactiStaph test for the Staphylococcus genus (in this case S. aureus)
(Summers, Brookings and Waites, 1998). Which relies on the principle of detecting coagulase
(clumping factor) using fibrinogen, and detecting protein A with immunoglobulin G. As result of
these surface markers present on most strains of S. aureus will test positive for BactiStaph test
(Summers, Brookings and Waites, 1998; Harris, Foster and Richards, 2002); Another test to
differentiate E. coli and B. cereus from S. aureus is by the basis of motility. Using either MAST
motility test or hanging drop method differentiate E. coli and B. cereus from S. aureus, as the two
bacteria are motile (Mitchell and Kogure, 2006); Lastly, since neither E. coli nor S. aureus produce
endospores, whilst B. cereus under the right conditions does produce endospores. By using
techniques such as Dipicolinic acid assay or Schaeffer–Fulton spore stain can be used to assess the
presence of spores in B. cereus (Hindle & Hall, 1999).
Three plating methods can be used to produce well separated single colonies, streak plate procedure,
spread plate and the pour plate procedure (Sanders, 2012). Spread plate procedure is used to
separate microbes contained within a small sample volume (e.g. mixed broth culture) which is then
spread over an agar

Lab Report : Chemical Synthesized Nanoparticles
V. Discussion Chemical synthesized nanoparticles raises certain toxicity issues that lead to
development of eco–friendly methods to synthesize silver nanoparticles. Green synthesis of silver
nanoparticles using plant extract is eco–friendly nanoparticle synthesis approaches (13). This is one
step reaction as reducing and stabilization agents both are present in the plant extract. Silver nitrate
and extract when mixed together forms light yellow coloured solution in starting that turns into dark
brown solution later. The appearance of a dark–brown color in solution containing the extract and
silver nitrate was a clear indication of the formation of AgNPs in the reaction mixture. Nanoparticle
shape and size as observed by TEM reveled that these particles are not perfectly spherical but also
have quasi–spherical, triangular and pentagonal shapes. Heterogeneous particles formation occurs
due to rapid utilization of the capping molecules. Particles formed later are with less capping
molecules and becomes thermodynamically unstable. These particles with less number of capping
molecules then tends to minimize high surface energy and gets shape of a triangle or pentagonal
having smooth angles (14, 15). XRD analysis and peak matching with similar AgNPs confirmed the
crystalline structure of AgNPs. Two extra peaks present in the XRD spectra marked by star indicate
the presence of biological moieties in the AgNPs (14). Hence, biological functional group
involvement in

Sepsis: Diagnostic And Therapeutic Challenges
Sepsis, a potentially life–threatening complication of an infection, occurs when chemicals are
released into the bloodstream to fight infection. These chemicals trigger inflammatory responses
throughout the body (Mayo Clinic Staff, 2016). Sepsis can be triggered by any type of infection:
bacterial, viral, or fungal. Contrary to popular belief, sepsis is responsible for a great number of
deaths in the United States alone. Sepsis kills more than 258,000 Americans per year, is the number
one cause of death in hospitals, and kills more Americans than prostate cancer, breast cancer, and
acquired immunodeficiency syndrome (AIDS) combined. (Rory Staunton Foundation for Sepsis
Prevention, n.d.) As cited in nursing journal, "Sepsis: Diagnostic and Therapeutic Challenges," 'One
of the ... Show more content on Helpwriting.net ...
Pediatric sepsis can present itself in a number of ways, it is manifested by: rashes, changes in skin
color, decreased amount of urine, lethargy, fever above 1004 F, and disinterest or difficulty feeding,
among others (Rory Staunton Foundation for Sepsis Prevention, n.d.) When sepsis takes place, the
circulatory system is often the first system to become compromised. Tachycardia, tachypnea,
peripheral vasodilation, fever, or worst case scenario, circulatory collapse can happen (Santhanam,
2016). If continued, sepsis can eventually affect multiple organs, also known as multiple organ
dysfunction syndrome (MOBS), or worse lead to death. The signs and symptoms of sepsis reflect
the systemic inflammatory response syndrome (SIRS). As medical doctor Shankar Santhanam
(2016) states in the "Pediatric Sepsis," SIRS can be caused by infectious or

Observation Of Water In Sycamore Creek
On a still, warm morning our class set out on a hike to collect water and soil samples to explore. Our
water sample was collected from the first portion of Sycamore Creek located on the Los Penasquitos
Trail in Sorrento Valley. Collecting 6 in. deep into the creek, we wanted to ensure that the sample in
the plastic test tube included soil, algae and vegetation from the floor. The sample was allowed to sit
uncapped and covered with a layer of film for 24+ hours before microscopic observation occurred.
Expectedly, the soil and a variety of dense particles settled to the bottom of the test tube. Using a
pipette we drew water from the center of the sample, but making sure not to draw up any soil. Three
separate slides were prepared, each

Identification Of Unknown Bacteria Number 63 Essay
Ashley Whitehead
BIOL1134K–01
Dr. Balding
10 November 2016
Identification of Unknown Bacteria Number 63 The best and most accurate way of identifying an
unknown microorganism is by sequencing its DNA, but this is very expensive and only used in
highly qualified labs. So, the identification of unknown bacteria number 63 was be done by putting
the bacteria through numerous laboratory tests. Microorganisms are different among each other by
their macroscopic morphology, microscopic morphology, and the unique metabolic processes they
use to survive and reproduce. Identifying an unknown microorganism in the laboratory is important
because knowledge is gained on the appropriate way to cultivate an organism, how to correctly read
the result of a test, and learning about the different characteristics of the bacteria. All of the
following tests were done using the best sterile technique and the most new turbid bacterial growth
subculture. The detection of unknown bacteria number 63 began with examining macroscopic and
microscopic morphology. Macroscopic morphology of unknown bacteria was done by a streak for
isolation of bacteria on a plate with nutrient agar, which allowed the bacteria to ingest the nutrients
it needed to survive and reproduce to form pure colonies. After growth, the colonies appeared to be
mucoid, beige in color with smooth edges and no elevation. Another macroscopic test was done in a
tube with semi–solid agar to test for motility and the result of this test

Correlation Between A Cell And Its Background
Introduction:
When viewing live specimens with the microscope it can be very difficult to see. What makes slides
hard to examine is the contrast between a cell and its background, which are both primarily water. In
order to provide information and characteristics about the chemistry of a specimen a method called,
staining is used to increase its differences. Stains/dyes are a salt that colors the ion it penetrates.
There are two types of colors retrieved when staining; in a basic stain the color appears in the
positively charged ion, while in an acidic stain the color is in the negatively charged ion. Examples
of basic dyes include: methylene blue, crystal violet, and safranin. Generally, if a staining procedure
only uses one ... Show more content on Helpwriting.net ...
The three bacterial specimens used were: Escherichia coli, Bacillus subtilis, and Staphylococcus
aureus.
Materials:
– Microscope slides – Kem Wipes
– Broth of Escherichia coli – Broth of Staphylococcus aureus
– Broth of Bacillus subtilis – Inoculating loop
– Bunsen Burner – Rope connector for Bunsen Burner
– Test tube rack – Wax pencil
– Stain (methylene blue) – Compound Microscope
– Clothes pin
Procedure:
1. First and most importantly, hands and work area were sanitized with antiseptic and paper towel.
2. Collected all the materials needed, stated above, and placed them in the work area.
3. Cleaned a microscope slide with a Kem Wipe to avoid bacteria lingering in the air or fingerprints
being seen on it, and continued by adding one or two drops o f distilled water on to the slide.
4. On the opposite side of the slide drew a circle, with the wax pencil, for indication on where the
bacteria were being placed.
5. Assembled Bunsen burner and turned it on so that the flame observed on the inner portion was
light blue and outer portion was dark blue.
6. Once the desired flame was seen, sterilized the loop by placing it on a 45̊ angle so that the entire
piece of metal was sterilized. Waited until the loop turned a red/orange color, then removed it and
allowed the loop to cool off.
7. Made sure to keep the loop, slide, and specimens a couple inches near the flame in order to keep
them sterile.
8. Removed the broth of Bacillus subtilis from

Classification And Discussion Of Esterification
Results and discussion
Esterification extent:
The color reaction using hydroxylamine hydrochloride was used with modification to quantify the
extent of esterification of proteins and the results showed that the highest level of esterification was
recorded for esterified cowpea protein isolate (82%) followed by esterified common bean protein
isolate (79%).
Functional properties of native and modified proteins:
PH–solubility profile:
The pH–solubility curves of native and esterified cowpea protein are shown in Fig.1. The solubility
profile of native cowpea indicate that protein solubility reduced as the pH increased from 2 to 4,
which corresponding to its isoelectric point, after which subsequent increases in pH increased
protein solubility progressively. The minimum solubility for native cowpea (10 %) was at pH 4
which corresponds to its isoelectric point ( IP).The highest protein solubility (80%) was observed at
pH 10. Esterification increased protein solubility in the acidic pH range from 2 to 5. Increasing pH
more than 5 reduced the solubility and giving a minimum value (9 %) at pH 6. Methylated cowpea
protein was more soluble in the acidic range of pH and less soluble in the alkaline range of pH as
compared to unmodified protein. On the other hand The solubility profile of native common bean
indicate that protein solubility reduced as the pH increased from 2 to 5, which corresponding to its
isoelectric point, after which subsequent increases in pH increased protein

Test Tube # 13 Lab Report
Problem: An unknown bacteria in test tube #13 needs to be identified out of the list of bacteria
provided as possible.
Hypothesis: If different tests were carried out to identify the bacteria's characteristics, then the
bacteria could be identified, because a dichotomous key can be used to eliminate all other bacteria in
the list
Procedure:
1. Obtain an inoculating loop, Bunsen burner, test tube #13 and a test tube rack.
2. Gram Stain Test to determine the shape of the bacteria, it's orientation of growth, and whether is
gram–negative meaning the bacteria lacks a cell wall, or gram–positive which means it contains a
cell wall.
a. Obtain a clean slide, crystal violet, Gram's iodine, 95% alcohol, safranin, bibulous paper, a light
microscope along with materials from step 1.
b. Sterilize the inoculating loop in Bunsen burner and let cool.
c. Collect sample with the sterilized inoculating loop from test tube #13 after uncovering and
heating the top of the test tube, then spread onto a clean slide and let it dry.
d. Heat–fix the bacteria to the slide by passing the slide three times over the Bunsen burner flame,
but be careful not to destroy the bacteria by excessive heat.
e. Flood the slide with crystal violet and wait one minute.
f. Wash the slide off with tap water by letting a slow drip hit one end of the slide, and roll off the
other side by tipping ... Show more content on Helpwriting.net ...
The bacteria is not pathogenic on its own, however produces protein–toxins indirectly, disrupting
the host. The bacteria mainly affects the respiratory system of the nose, causes dermal infections.
This is one of the most common infections found in hospitals, which is spread by healthcare workers
acting as carriers for Staphylococci aureus. Staphylococci aureus has a thick cell wall, making it
hard for a body's immune system to destroy it, and has become commonly resistant to antibiotics,
leaving a need to newer generations as it evolves

Sample 70a Sample Lab Report
Shaquisha Lor #70
Dr. Birney
Sample A
Gram–positive Rods
Dichotomous Key
#70A Gram–positive Rods
B. subtilis
C. xerosis
B. Cereus
VP test B. subtilis C. xerosis B. cereus
DNase B. cereus B. subtilis
B. cereus Sample 70A was a given as a pure bacteria. With this pure bacterium I immediately made
a streak plate to get my single colonies and conducted a Gram stain. After completed the steps as
instructed in the Laboratory manual, it was determined that Sample 70A bacteria was a Gram–
positive rods. The bacteria was purple in color, this indicate that the crystal violet was not countered
with the safranin leaving bacteria stain with the crystal violet (Leboffe and Pierce). The cells were
cylinder in shape clarifying them as rods. ... Show more content on Helpwriting.net ...
I decided to conduct this particular stain due to the fact the Gram–positive bacteria, especially the
Bacillus species produce endospores (Leboffe and Pierce). The results from endospore test
concluded to be positive for endospores. The next step into determined which gram–positive rod
bacteria 70A contain, I conducted a Voges–Proskauer (VP) Test as instructed by the laboratory
manual. Upon completion of the VP test it was concluded that the bacteria was positive. For a
positive Voges–Proskauer test the broth has to turn red in color with a 60 min time period (Leboffe
and Pierce). Testing positive for VP narrowed the bacteria choices to B. subtilis and B. cereus. I
conducted the Oxidase test next and the results were unclear. After trying multiple times I concluded
that the test was positive. To verify my conclusion it conducted a DNase test to verify my choice.
The DNase test came back with a halo meaning the DNase test was positive. After completing these
tests, I have the determined that a bacterium Sample 70A is B. cereus. According to our class chart
B. cereus is positive for Oxidase and DNase

Taking a Look at Bacterial Endospores
Bacterial endospores are highly resistant structures that can withstand many forms of treatments,
including heat and UV (Atrih & Foster, 2002), and this characteristic is facilitated by their unique
spore structure. Bacterial capsules play an important role in the virulence of bacteria for their host,
and enable bacterial cells to evade host defense mechanisms and survive hostile environments. The
structure and function of endospores and capsules work specifically to benefit the microbial cell;
furthermore, various physiological changes occur in these structures as a result of environmental
stress (Sahin, et. Al., 2012). The specific mechanism of these physiological changes, the types of
environmental stresses that cause the changes, and how these correlate with endospore and capsular
structure and function are essential to the understanding of this topic. Bacterial endospores are
dormant, non–reproductive, and sometimes disease–causing cell structures that are typically formed
in Gram–positive bacteria under a process called sporulation. Endospores exhibit high resistance to
environmental stresses, and these structures are able to resist conditions that are unfavourable to
most organisms, enabling bacteria to lie dormant for extended periods of time (hundreds to
thousands of years). In addition, endospores are highly durable, as dormant spores return to an
actively growing state a process called germination) when nutrients return to their environment.
Sporulation is

Staphylococcus Aureus

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