Introduction of experiment
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This document discusses the importance of soil as a nutrient-rich medium for plants and a habitat for various bacteria. It details an experiment conducted to identify and compare bacterial populations in normal soil versus chicken farm soil, showing that chicken farm soil is more contaminated due to its higher nutrient content. The study employed techniques such as serial dilution, spread plating, and various staining methods to analyze microbial diversity and contamination levels.
Introduction of experiment
- 1. Introduction Soil is an important source which is rich of nutrients for plants. Besides that, soil also act as an excellent medium that suitable for various type of bacteria to survive. The identities of microbes that survived in soil are unable to determine directly as there are A huge number of species of bacteria contained in this medium. To study the level of contaminated of soil by microbes and the types of the bacteria that survive in different types of condition, the selective condition is provided to carry out the experiment. Since the identification and comparison, the types of microbes that survived in soil cannot be determined directly, therefore a series of an experiment is carried out. Isolation of microbes from two soil sample which is normal soil and chicken farm soil is done by using the technique of serial dilution and spread plate. The series of dilution in tubes were 10-2 ,10-3 , 10-4 ,10-5 , and 10-6 and transfer them into a nutrient agar plate and nutrient agar plate with 7.5% NaCl after each dilution. After incubation of the plates, the enumeration of microorganisms is started by technique of standard Plate Count and identification of colony morphology. The colonies which grew in agar plate streak into new agar plate which is a pure culture for microbes and incubated it. Lastly, identification and differentiation of microorganisms with using simple stain, gram stain and endospore stain methods. In the gram stain, crystal violet dye, gram’s iodine and counterstain safranin are used to differentiated whether the microbes contain in both soils are gram-positive or negative bacteria. However, endospore stain is to determine the present of endospore in the bacteria with using counterstain safranin and malachite green dye. From this experiment, we can conclude out the level of contaminated of soil with different condition and also the types of the bacteria that survive in different types of condition. From these two issues, we can that chicken farm soil is more contaminated by bacteria than normal soil as chicken farm soil provide higher nutrients to bacteria that normal soil. As we can have counted the number colony from in the plates with a higher dilution of bacteria is the lowest number of population of bacteria. Besides that, chicken farm soil is more contaminated than the normal soil, thus the amount and types of microbes will be higher in normal soil. Furthermore, the growth of microbes in plate agar with 7.5 % of NaCl will be more active than the normal nutrient agar. Thus, microbes are more flavour to survive in salty media they are gram negative bacteria which have thin cell wall than the gram positive bacteria. There are not only vegetative endospores bacteria live in soil but also the bacteria without endospore. In short, soil is a media that rich of different species of microbes that we can explore.