Isolation, Screening, and Characterization of Biosurfactant-Producing Microorganisms from Petroleum-Contaminated Soil and Further Optimization of Parameters for Biosurfactant Production

© 2018, IJPBA. All Rights Reserved 53
Available Online at www.ijpba.info
International Journal of Pharmaceutical Biological Archives 2018; 9(3):53-59
ISSN 2581 – 4303
RESEARCH ARTICLE
Isolation, Screening, and Characterization of Biosurfactant-Producing
Microorganisms from Petroleum-Contaminated Soil and Further Optimization of
Parameters for Biosurfactant Production
Swarda Deo and Pooja Rana*
Department of Biotechnology, Modern College of Arts, Science and Commerce, Ganeshkhind, Pune - 411 0 14,
Maharashtra, India
Received: 30 May 2018; Revised: 28 June 2018; Accepted: 25 July 2018
ABSTRACT
Introduction: Biosurfactants are amphiphatic in nature and are surface-active compounds produced by
microorganisms.Thesemoleculesreduceinterfacialsurfacetensionbetweenaqueoussolutionsandhydrocarbon
mixtures. Unfortunately, oil spills and industrial discharges from petroleum-related industries have been
identified as the major pollution sources.The hydrophobicity and low aqueous solubility of petroleum pollutant
limit the biodegradation process. The features that make biosurfactants as an alternative to commercially
synthesized surfactants are its low toxicity, higher biodegradability and, hence, greater environmental
compatibility,betterfoamingproperties,andstableactivityatextremepH,temperature,andsalinity.Objective:
Therefore, in this study, hydrocarbon-degrading bacteria were screened from petroleum-contaminated soil,
characterized and optimization of the physical and nutrient parameters were done to enhance the production
of biosurfactants. Results: Petroleum-contaminated soil was collected from different petrol pumps in Pune
and screening was done on minimal salt medium media containing palm oil as carbon source using hemolytic
activity, emulsification index, drop-collapse test, and oil displacement method. The most promising strain was
isolated and identified using Bergey’s Manual of Determinative Biology and 16s rRNA sequencing and was
found to be Staphylococcus epidermidis. The optimization of various parameters, namely temperature, pH,
carbon, and nitrogen sources on growth, and biosurfactant production was studied. The highest biosurfactant
production was obtained when MSS media contains sucrose (carbon source) and urea (nitrogen source) at pH
10 and temperature 55°C. The Fourier transform-infrared (FT-IR) analysis of purified biosurfactant indicated
the presence of lipopeptide biosurfactant when compared with reference FT-IR spectra.
Keywords: Biodegradation, biosurfactants, emulsification, petroleum, screening, soil
INTRODUCTION
Biosurfactants or microbial surfactants are
surface-active molecules that are produced by a
variety of microorganisms including bacteria,
yeast, and filamentous fungus. Due to their
amphipathic nature, these biomolecules reduce
the interfacial tension between an aqueous phase
and hydrophobic molecules, thereby enhancing
the solubility and bioavailability of hydrophobic
organic compounds.[1]
However, biosurfactants
have not yet been commercialized extensively
due to low production yields and high feedstock
and purification costs.[2,3]
Due to environmental
*Corresponding Author:
Dr. Pooja Rana,
E-mail-pooja.pathania@gmail.com
issues and restrictive laws, the demand for
biodegradable surfactants is increasing. The
use of these biocompounds as an alternative to
the traditional chemical surfactants has been
impelled by the fast progress of biotechnology
and also by their interesting features including
their lower toxicity, higher biodegradability, and
effectiveness at extreme temperature, salinity, and
pH conditions [4]
Biosurfactants are mainly categorized by their
chemical composition and microbial origin. In
general, their structure includes a hydrophilic
moiety consisting of amino acids or peptides,
mono-, di-, or poly-saccharides and hydrophobic
moiety comprising saturated or unsaturated
fatty acids. A
major class of biosurfactants
includes - glycolipids,phospholipids,fattyacidand
natural lipids, peptides, polymeric biosurfactants,

Deo and Rana: Isolation, screening, and characterization of biosurfactant-producing microorganisms from petroleum-
contaminated soil and further optimization of parameters for biosurfactant production
IJPBA/Jul-Sep-2018(Suppl)/Vol 9/Issue 3 54
and particulate biosurfactant. Among the
various classes of biosurfactants
-
rhamnolipids
and surfactins are best-studied biosurfactants.
Rhamnolipid is one of the types of glycolipids, in
which one or two molecules of rhamnose are linked
to one or two molecules of β-hydroxydecanoic
acid while the
-OH group of one of the acids
is involved in glycosidic linkage with the
reducing end of the rhamnose disaccharide, in
ester formation. Rhamnolipids are produced
by Pseudomonas aeruginosa, Gram-negative,
motile, and non-spore-forming bacteria. Surfactin
is a cyclic lipopeptide commonly used as an
antibiotic. In the various course of studies of its
properties, surfactin was found to exhibit effective
characteristics such as antibacterial, antiviral,
antifungal, antimycoplasma, and hemolytic
activities. Surfactin is produced by Bacillus
subtilis, Gram-positive, motile, and spore-forming
bacteria. Surface activity in most hydrocarbon-
degrading microorganisms is attributed to several
cell surface constituents, which includes structures
such as M protein and lipoteichoic acid in Group A
Streptococci, Protein A in Staphylococcus aureus,
Layer A in Aeromonas salmonicida, prodigiosin
in Serratia spp., gramicidins in Bacillus brevis
spores, and thin fimbriae in A. calcoaceticus.[5]
The oil and gas industry is one of the most
important sectors in India. Unfortunately, oil
spills and industrial discharges from petroleum-
related industries have been identified as
the two major sources of pollution. The
biodegradation of petroleum pollutant is limited
by its poor availability to the microorganisms,
its hydrophobicity, and low aqueous solubility, [6]
The applications of biosurfactants are not limited
to bioremediation purposes, but they can be
used in petroleum engineering to reduce heavy
oil viscosity, clean oil storage tanks, increase
petroleum transport in pipelines, and stabilize
fuel water-oil emulsions.[7]
The features that make
biosurfactants as an alternative to commercially
synthesized surfactants are its low toxicity, higher
biodegradabilityand,hence,greaterenvironmental
compatibility, better foaming properties (useful in
mineral processing), and stable activity at extreme
pH, temperature, and salinity.[8]
Biosurfactants
also found to be important in therapeutic and
biomedical field as they possess antimicrobial,
antiviral, and antifungal properties also they
inhibit fibrin clot formation and have antiadhesive
properties. These biomolecules can replace the
harsh surfactants, presently being used in million
dollar pesticide industries.[9]
To reduce the production costs, different routes
could be investigated such as the increase of
yields and product accumulation, the development
of economical engineering processes, and the
use of cost-free or cost-credit feedstock for
microorganism growth and surfactant production.
The choice of low cost or waste substrates is
important to overall economy of the process, and
they account for 30–50% of final product cost and
also minimize the expenses cost of waste treatment.
[10-12]
Hydrocarbons such as crude oil and diesel and
various carbohydrates such as glucose, sucrose, and
glycerol have been commonly used as substrates
for the production of biosurfactants. Since the
biological function of biosurfactant is related to
hydrocarbon uptake, a spontaneous release occurs
with these substrates,
[13]
It is well known that
combination of different environmental factors
such as temperature, pH, salinity, and hydrocarbon
toxicity would affect growth of microorganisms,
hence, the amount of their bioproducts. The
combination of these constraints can be expected
to limit the number of suitable organisms that
would grow and produce bioproducts.[14]
The
objective of this study is, therefore, to screen
hydrocarbon-degrading bacteria from petroleum-
contaminated soil and to optimize the physical and
nutrient parameters to enhance the production of
biosurfactants.
MATERIALS AND METHODS
Isolation of organisms from soil
Soil samples were collected from different petrol
pumps in Pune, India. All the samples were
collected using polyethylene containers with
utmost care to avoid contamination. 1 g of soil
sample was taken and serially diluted in 0.85%
sterile saline. Flasks were maintained in a shaker
with 150 rpm at room temperature for 4 days.
Screening was performed using serial dilutions of
the sample and plating on minimal salt medium
(MSM) with palm oil (1% w/v) as carbon
source for the isolation of bacteria. The MSM
of following composition was used (g/L) - 0.8 g
dipotassium hydrogen phosphate (K2
HPO4
), 0.2 g
potassium dihydrogen potassium (KH2
PO4
),

0.05 g calcium chloride (CaCl2
), 0.5 g magnesium
chloride (MgCl2
), 0.01 g ferric chloride (FeCl2
),
1 g diammonium sulfate (NH4
)2
SO4
), and 5 g
sodium chloride (NaCl). Plates were incubated at
37°C for 72 h. Different bacterial colonies were
selected based on the colony morphology and
then streaked on nutrient agar. Morphologically,
distinct colonies were reisolated by transferring
them to fresh palm oil containing agar plates at
least 3 times to obtain pure cultures. The colonies
were then screened for biosurfactant production.
Screening for biosurfactant activity
Hemolytic activity
Pure culture of bacterial isolates was streaked on
the freshly prepared blood agar plates containing
5% sheep blood and incubated at 37°C for 48 h.
Results were recorded based on the type of zone of
clearance observed, i.e. α-hemolysis when colony
was surrounded by greenish zone, β-hemolysis
when colony was surrounded by clear white zone,
and γ-hemolysis when there was no change in
the medium surrounding the colony.[15]
This is
preliminary method for screening biosurfactant
activity.
Emulsification index (%EI 24
)
Colonies of pure culture were suspended in test
tube containing 2 ml of MSM and incubated at
37°C for 24 h. 2 ml hydrocarbon (oil) was added
to each tube. Then, the mixture was vortexed at
high speed for 2 min and allowed to stand for 24 h
at room temperature and emulsification index was
calculated. The %EI24
was calculated by dividing
the height of emulsified layer (mm) by total height
of the liquid in tube (mm) and then multiplying
by100.[16]
Emulsification
index E24
Height of emulsion layer
Total h
( )=
e
eight
×100
Drop-collapse test
The cultures that showed hemolytic activity
and emulsification index were grown in MSM
supplemented with 1% palm oil for 48 h at room
temperature for drop-collapse test. Screening of
biosurfactant production was performed using
the qualitative drop-collapse test described by
Bordour and Maier.[17]
2 µl of palm oil was added
to each well of 96-well microtiter plate lid and
these were left to equilibrate for 24
h. 5 µl of
cultural supernatant was added to the surface of
oil and drop size was observed after 1 min. The
result was considered positive for biosurfactant
production and flat rounded drops indicated lack
of biosurfactant production.[18]
Oil displacement method
20 µl of palm oil was placed on surface of distilled
water (20 ml) in a Petri dish, then 20 µl of culture
supernatant was gently put on center of oil film. If
the biosurfactant is present in the supernatant, the
oil is displaced and diameter of the clear hallow
area visualized under visible light was measured
and calculated after 30 s.[19]
Identification of biosurfactant-producing
bacteria
Based on the screening test results, the positive
isolates were inoculated into the mineral salt
medium for the biosurfactant production. Based
on the quantification of biosurfactant produced,
the best strain was selected and then identified
by its microscopic appearance and biochemical
tests based on Bergey’s Manual of Determinative
Bacteriology. In addition to morphological
and biochemical tests, the phylogeny of strain
is determined using sequence analysis of
polymerase chain reaction (PCR) amplified
16s rRNA gene using the primer pair RPP2
(CCAAGCTTCTAGA CGGITACCTTGTTA
CGACTT) and FDD2 (CCGGATCCGTCGACA
GAGTTTGATCI TGGCTCAG). RPP2 and
FDD2 are universal primers for 1.5 kb fragment
amplification for eubacteria. The following PCR
conditions were used: 95°C for 5 min, followed
by 25 cycles of 95°C for 1 min, 50°C for 30 s, and
72°C for 5 min, followed by 72°C for 5 min. After
completion of PCR amplification, the samples
were purified and loaded on the sequencer - Avant
3100 Gene Analyzer. The sequencing output was
analyzed using the accompanying DNA Sequence
Analyzer computer software. The sequence was
compared with National Center for Biotechnology
Information GenBank entries using BLAST
algorithm.

Effect of temperature, pH, carbon, and
nitrogen sources on growth and biosurfactant
production
Optimization study was conducted to find out the
optimum conditions for the large-scale production
ofbiosurfactant.Theselectedisolatewasinoculated
in 100 ml of minimal salt media in 250 ml flask,
and the pH of the media was adjusted to 4, 6, 8,
10, and 12, and incubated for 48 h. The cells were
removed by centrifugation, and supernatant was
used for the estimation of biosurfactant production
by measuring OD at 420 nm. Similarly, a range
of different temperatures was used (15°C, 25°C,
35°C, 45°C, and 55°C) to find the optimum
temperature.
Growth and biosurfactant production by the isolate
was evaluated using mineral salt media (MSS)
with different carbon and nitrogen sources. The
MSS consisted of gl−1
:NaCl 10.0; Na2
HPO4
5.0;
KH2
PO4
2.0; and MgSO4
7H2
O 0.2. The carbon
sources used were sodium acetate, paraffin,
sucrose, and starch using ammonium nitrate as the
nitrogen source (2/g). The different carbon sources
were added to MSS at a concentration of 10/gl. The
different nitrogen sources used were - ammonium
sulfate, ammonium nitrate, sodium nitrate, and urea
while sucrose is used as carbon source (10/gl).The
nitrogen sources added to MSS at a concentration
of 2/gl.All media were adjusted to a pH of 7.Assays
were performed in 100 ml flasks containing 50 ml
of different media. Each flask was inoculated with
1% of preculture grown in same medium for 24 h.
Cultures were incubated at 40°C without shaking
for 120 h. After every 24 h, samples were taken,
centrifuged at 10,000, 20 min, 20°C, and cell-free
supernatants were used to measure biosurfactant
production using various parameters.
Extraction and purification of biosurfactant
Biosurfactant for chemical composition analysis
was extracted from cell-free supernatant using
Folch extraction method that is commonly used
to extract lipids from biomolecules.[20]
Briefly, a
chloroform/methanol mixture (2:1) was added
to supernatant sample to a final chloroform/
methanol/water ratio of 8:4:3. The mixture was
centrifuged (9000 g, 5 min), the organic layer was
collected, and samples were evaporated to dryness
under N2
at 37°C for 30 min.
Fourier transform-infrared (FTIR)
Spectroscopy
FTIR is most useful for identifying types of
chemical bonds (functional groups) and therefore
can be used to elucidate some components of
the unknown sample. 10 mg of freeze-dried
pure biosurfacant was grounded with 100 mg
of KBr and pressed with 7500 kg for 30 s to
obtain translucent pellets. The FTIR spectra, with
resolution of 1/cm, were collected from 400 to
4000 wavenumbers (cm−1
) and are an average of
128 scans using a Tensor 27 infrared spectrometer
operating in attenuated total reflection mode.
RESULTS AND DISCUSSION
Biosurfactants play an important role in
food industry, bioremediation, food industry,
pharmaceuticals, oil industry, petrochemistry,
paper, and pulp industry.[21]
Furthermore, due to
diversity of microorganisms and different niches,
they inhabit that there is need of efficient isolation,
screening, and optimization of biosurfactant-
producing bacteria from the natural environment.
In the present study, the contaminated soil was
collected from various petrol pumps. A
total of
29 strains were isolated from the soil sample
and screened for biosurfactant production using
various screening tests, and it was found that only
17 colonies were positive in the primary screening
through hemolytic activity in blood agar plate. The
hemolytic activity was first studied by Bernheimer
andAvigad[22]
in B. subtilis. Carrillo et al.[15]
found an
associationbetweenhemolyticactivityandsurfactant
production, and they recommended the use of blood
agar lysis as a primary screening method. All the 17
strains were further screened by drop-collapse test
to confirm biosurfactant production, and the results
revealed only 10 colonies were potent biosurfactant
producers. Bodour et al.[16]
used drop-collapse
assay and found that only biosurfactant-producing
organisms formed microemulsion in this assay
[Table 1]. For screening of biosurfactant-producing
isolates,theyemulsifiedthecoatedoilinculturebroth
and made microemulsion, because of the formation
of microemulsion, the culture drops collapsed in
coated oil. The presence of organisms present in
the soil depends on the nature and nutrient content
of the soil. These colonies were further screened to
select the most potent biosurfactant producer. For the

detection of potential strain, E24 value of the isolates
was compared. It was found that strain C8 showed
77.77% emulsification, which was significantly high
compared to otherstrains[Table 1].From10selected
colonies, therefore, only one colony was selected
as a highly potent biosurfactant producer based on
emulsification (77.77%), oil spread (1.7 cm), drop
collapse, and hemolytic activity (α-hemolysis).
The strains showed α, γ, or no hemolysis [Table 1].
The potent strain was characterized by standard
bacteriological procedure through biochemical
tests, and the results were interpreted with Bergey’s
ManualofDeterminativeBiologyandwereidentified
to be Staphylococcus spp. [Table 2]. For further
identification and phylogenetic relation analysis,
16s rRNA sequencing was performed which shows
that isolated biosurfactant-producing bacteria was
Staphylococcus epidermidis [Figure 1].
Effect of pH and temperature on biosurfactant
production
The applications of biosurfactants in various fields
depend on their stability at different ranges of
temperature and pH. The stability of biosurfactant
was tested over a wide range of temperature
ranging from 15°C to 55°C and pH 4–12. The pH
of the medium was important characteristic for cell
growth of organism and production of secondary
metabolites. At pH 5, the biosurfactant production
was severely decreased, and the cell growth
was significantly retarded. This low pH created
unfavorable growth conditions for the bacterial
population. When the initial pH was set to 8, the
emulsification activity increased (E24 = 45.45%).
In case of S. epidermidis, the emulsification
activity was 51.25% for pH 10 [Figure 2a]. The
emulsification index decreased with any further
increase in pH.Therefore, it was concluded that any
change to both lower and higher pH values caused
an appreciable drop in biosurfactant production.
Temperature is one of the critical parameters
that greatly affected the culture growth and the
biosurfactant production. The results in the present
study revealed that the biosurfactant activity
reached the highest for the isolate S. epidermidis
grown at 45°C (E24 = 55%) followed by E24 =
Table 1: Comparison of emulsification, oil spreading, drop collapse, and hemolytic activity of the 10 isolated strains from
petroleum‑contaminated soils
Colony number E24
% Oil spreading (cm) Drop collapse Hemolysis
C1 24.24 0.25 + α‑hemolysis
C2 37.83 1.9 + No hemolysis
C3 2.57 0 ‑ No hemolysis
C4 57.14 2 ++ α‑hemolysis
C6 21.21 1.65 ‑ No hemolysis
C8 77.77 1.7 +++ α‑hemolysis
C10 45.71 1.9 ++ γ‑hemolysis
Table 2: Biochemical characterization of the selected
strain (C8)
Characteristics/test Result
Shape Circular
Size 0.1 cm
Margin Smooth
Elevation Flat
Color Pale yellow
Opacity Translucent
Consistency Soft
Gram stain +
Catalase +
Oxidase -
Motility -
Figure 1: Unrooted phylogenetic tree based on 16s rRNA
gene comparison of the biosurfactant-producing bacteria
isolated from petroleum-contaminated soil and the nearest
relative in Genbank, only values 50% are given. NCBI
accession numbers are given

50% at 25°C, and this clearly indicates moderately
thermostable nature of biosurfactant [Figure 2b].
When the incubation temperature increased
to 55°C, bacterial growth and biosurfactant
production were totally inhibited, indicating that
the biosurfactant production by S. epidermidis is
greatly reduced at high temperature.
Effect of carbon and nitrogen sources on
biosurfactant production
Biosurfactants can only act as substitutes of
synthetic surfactants if the cost of the raw material
isminimal.Theuseofvariousalternativesubstrates
is one of the attractive strategies for economical
biosurfactant production. The production of
biosurfactant was found to be dependent on the
composition of the medium. The MSS media
optimization was carried out using various carbon
sources, namely sodium acetate, paraffin, sucrose,
and starch using ammonium nitrate as nitrogen
source. The highest biosurfactant production
was achieved using sucrose (10% w/v) being the
sole source of the carbon [Figure 3a]. Various
nitrogen sources selected were ammonium
sulfate, ammonium nitrate, sodium nitrate, and
urea using sucrose as carbon source, and highest
biosurfactant production was observed with
urea as nitrogen source [Figure 3b]. The highest
biosurfactant production obtained when MSS
media contains sucrose (carbon source) and urea
(nitrogen source) at pH 10 and temperature 55°C.
FTIR analysis
Purification of biosurfactant was carried out
using Folch extraction method and characterized
using FT-IR analysis. It was observed that
characteristic absorbance bands of peptides at
3435–3404.47/cm (NH stretching mode); C-O
stretching mode (aromatic) at 1259.56/cm; and
C=C stretching mode was observed at 1614–
1642/cm. The presence of vinyl chains (HC=CH2
)
was confirmed at 2975/cm [Figure 4].
The FT-IR analysis indicates the presence of
aromatic hydrocarbons combined with a peptide
moiety that is characteristic of lipopeptide
Figure 2: (a) Effect of pH on biosurfactant production as
measured by emulsification index (E24%). (b) Effect of
temperature on biosurfactant production as measured by
emulsification index (E24%)
Figure 3: (a) Effect of different carbon sources on
biosurfactant production as measured by emulsification
index (E24%). (b) Effect of different nitrogen sources on
biosurfactant production as measured by emulsification
index (E24%)
Figure 4: Fourier transform infrared spectra of crude biosurfactant extracted from Staphylococcus epidermidis
a b
a b

biosurfactant when compared with reference FT-
IR spectra.[23]
ACKNOWLEDGMENT
The authors wish to thank Modern College ofArts,
Science and Commerce, Ganeshkhind, Pune, for
providing necessary facilities for carrying out the
research work.
REFERENCES
1. Mulligan CN. Recent advances in the environmental
applications of biosurfactants. Curr Opin Colloid
Interface Sci 2009;14:372-8.
2. Banat IM, makkar RS, Cameotra SS. Potential
commercial applications of microbial surfactants. Appl
Microbiol Biotechnol 2000;53:459-508.
3. Mukherjee S, Das P, Sen R. Towards commercial
production of microbial surfactants. Trends Biotechnol
2006;24:509-15.
4. Van Hamme JD, Singh A, Ward OP. Physiological
aspects. Part 1 in a series of papers devoted to surfactants
in microbiology and biotechnology. Biotechnol Adv
2006;24:604-20.
5. Singh V. Biosurfactant – isolation, production,
purification and significance. Int J Sci Res Publ
2012;2:1-4.
6. Das N, Chandran P. Microbial Degradation of petroleum
hydrocarbon contaminants: An overview. Biotechnol
Res Int 2011;2011:1-13.
7. Banat IM, Frazetti A, Gandolfil I, Bestetti G,
Martinotti MG, Fraccia L, et al. Microbial biosurfactant
production, applications and future potential. Appl
Microbiol Biotechnol 2010;87:427-44.
8. Marchant R, Banat I. Biosurfactants: A sustainable
replacement for chemical surfactants-review.
Biotechnol Lett 2012;34:1597-605.
9. Sachdev D, Cameotra S. Biosurfactants in agriculture:
A mini-review. Appl Microbiol Biotechnol
2013;97:1005‑16.
10. Kovare SS, Mahadik KR, Chopade BA. Studies on the
bioemulsifier production from marine Streptomyces sp
S1. Ind J Biotech 2007;6:78-84.
11. Ruggeri C, Franzetti A, Bestetti G, Caredda P, La
Colla P, Pintus M, et al. Isolation and characterisation
of surface active compound-producing bacteria
from hydrocarbon-contaminated environments. Int
Biodeterior Biodegrad 2009;63:936-42.
12. Maneerat S, Phetrong K, Song K. Isolation of
biosurfactant producing marine bacteria and
characteristics of selected biosurfactant. J Sci Technol
2007;29:781-91.
13. Desai JD, Banat IM. Microbial production of surfactants
and their commercial potential. Microbiol Mol Biol
Rev 1997;61:47-64.
14. Joshi S, Bharucha SJ, Yadav A, Nerurkar A, Desai J.
Biosurfactant production using molasses and whey
under thermophilic conditions. Bioresour Technol
2008;99:195-9.
15. Carrillo PG, Mandaraz C, Pitta-Alvarez SI, Giulie AM.
Isolation and selection of biosurfactant producing
bacteria 1996. World J Microbiol Biotechnol
1996;12:82-4.
16. Bodour AA, Drees KP, Maier RM. Distribution of
biosurfactants producing bacteria in undisrbed and
contaminated arid South Western soils. Appl Environ
Microbiol 2004;69:3280-7.
17. BordourA, Maier RM.Applications of a modified drop-
collapse technique for surfactant quantification and
screnning of biosurfactant producing microorganisms.
J Microbiol Methods 1998;32:273-80.
18. Youssef NH, Duncan KE, Nagle DP, Savage KN,
Knapp RN, McInerney MJ. Comparision of methods
to detect biosurfactant production by diverse
microorganism. J Microbiol Meth 2004;56:339-47.
19. Morikawa M, Hirata Y, Imanaka T. A study on
the structure function relationship of lipopeptide
biosurfactant. Biochem BiophysActa 2000;1488:211‑8.
20. Folch J, Lees M, Stanley GH. A simple method for the
isolation and purification of total lipids from animal
tissues. J Biol Chem 1957;226:497-509.
21. Rodrigues LR, Teixeira JA, van der Mei HC, Oliveira R.
Physicochemical and functional characterization of
a biosurfactant produced by Lactococcus lactis 53.
Colloids Surf B Biointerfaces 2006;49:79-86.
22. Bernheimer AW, Avigad LS. Nature and pro perties of
a cytolytic agent produced by Bacillus subtilis. J Gen
Microbiol 1970;61:361-9.
23. Faria AF, Martinez DS, Barbosa GN, Vaz BG,
Silva IS, Garcia JS et al. Production and structural
characterization of surfactin (C14/Leu7) produced
by Bacillus subtilis isolate LSFM-05 grown on raw
glycerol from the biodiesel industry. Proc Biochem
2011;46:1951-7.

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Isolation, Screening, and Characterization of Biosurfactant-Producing Microorganisms from Petroleum-Contaminated Soil and Further Optimization of Parameters for Biosurfactant Production