An efficient biosurfactant-producing bacterium Selenomonas ruminantium CT2, isolated from mangrove sediment in south of Thailand

Biosurfactant-producing bacteria, isolate CT2, was isolated from mangrove sediment in the south of Thailand. The sequence of the 16S rRNA gene from isolate CT2 showed 100?% similarity with Selenomonas ruminantium. The highest biosurfactant production (5.02?g/l) was obtained when the cells were grown on minimal salt medium containing 15?g/l molasses and 1?g/l commercial monosodium glutamate supplemented with 1?g/l NaCl, 0.1?g/l leucine, 5?% (v/v) inoculum size at 30?°C and 150?rpm after 54?h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5?mN/m), a small CMC value (8?mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test, FT-IR, MNR and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and also had the ability to emulsify oil and enhance PAHs solubility.     

Isolation and characterization of a biosurfactant from Deinococcus caeni PO5 using jackfruit seed powder as a substrate

Biosurfactant-producing bacteria were isolated from various sources in the south of Thailand. Isolates were screened for biosurfactant production using jackfruit seed powder (JSP) as a novel and promising substrate. The highest biosurfactant activity was obtained with a bacterial strain which was identified by 16S rRNA gene sequence analysis as Deinococcus caeni PO5. D. caeni PO5 was able to grow and reduce the surface tension of the culture supernatant from 67.0 to 25.0 mN/m after 87 h of cultivation when 40 g/l of JSP and 1 g/l of commercial monosodium glutamate were used as carbon and nitrogen sources, respectively. The biosurfactant obtained by ethyl acetate extraction showed high surface tension reduction (47.0 mN/m), a small critical micelle concentration value (8 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity, and a high level of salt tolerance. Chemical characterization by biochemical testing, Fourier transform infrared spectroscopy, and mass spectra revealed that the obtained biosurfactant was a glycolipid-type biosurfactant. The obtained biosurfactant was capable of forming stable emulsions with various hydrocarbons and had the ability to enhance oil recovery, the solubility of polyaromatic hydrocarbons, heavy metal removal, and antimicrobial activity.     

Production and characterization of biosurfactant from marine bacterium Inquilinus limosus KB3 grown on low-cost raw materials

Inquilinus limosus strain KB3, isolated from marine sediment in the south of Thailand, was used to produce a biosurfactant from a mineral salts medium (MSM) with palm oil decanter cake (PODC) as a carbon source. It was found that cellular growth and biosurfactant production in MSM were greatly affected by the medium components. I. limosus KB3 was able to grow and to produce surfactant reducing the surface tension of medium to 28.2 mN/m and giving a crude surfactant concentration of 5.13 g/l after 54 h. The biosurfactant obtained was found to reduce the surface tension of pure water to 25.5 mN/m with the critical micelle concentration of 9 mg/l, and retained its properties during exposure to elevated temperatures (121 °C), high salinity (12 % NaCl), and a wide range of pH values. Chemical characterization by FT-IR, NMR, and ESI-MS revealed that the biosurfactant has a lipopeptide composition with molecular mass (m/z) of 1,032. The biosurfactant was capable of forming stable emulsions with various hydrocarbons and had the ability to enhance oil recovery, PAHs solubility, and antimicrobial activity.     

Isolation of biosurfactant-producing <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> RS29 from oil-contaminated soil and evaluation of different nitrogen sources in biosurfactant production

An efficient biosurfactant-producing native Pseudomonas aeruginosa RS29 has been isolated from crude oil contaminated soil. Isolation was followed by optimization of different factors to achieve maximum production of biosurfactant in terms of surface tension reduction (STR) and emulsification index (E24). The isolated strain produced highest biosurfactant in the presence of glycerol after 48 h of incubation at 37.5°C, with pH range of 7–8 and at salinity <0.8% (w/v). The extent of STR and the E24 of medium with different nitrogen sources were investigated and found to be maximal for sodium nitrate (26.3 mN/m, E24?=?80%) and potassium nitrate (26.4 mN/m, E24?=?79%). The production of biomass by the designated strain was found to be maximal in ammonium-nitrate-containing medium as compared to the other nitrogen sources. A kinetic study revealed that biosurfactant production is positively correlated with growth of P. aeruginosa, and highest STR was achieved (27.0 mN/m) after 44 h of growth. The biosurfactant was produced as a primary metabolite and 6 g/L crude biosurfactant was extracted by chloroform:methanol (2:1). The critical micelle concentration of the biosurfactant was 90 mg/L. The absorption bands of the FTIR spectra confirmed the rhamnolipid nature of the biosurfactant. The biosurfactant was thermostable (up to 121°C for 15 min) and could withstand a wide range of pH (2–10) and NaCl concentration (2%–10% w/v). The extracted biosurfactant had good foaming and emulsifying activities and was of satisfactory quality in terms of stability (temperature, pH and salinity) and foaming activity.     

Production of biosurfactant and antifungal compound by fermented food isolate Bacillus subtilis 20B

A biosurfactant producing strain, Bacillus subtilis 20B, was isolated from fermented food in India. The strain also showed inhibition of various fungi in in-vitro experiments on Potato Dextrose Agar medium. It was capable of growth at temperature 55 degrees C and salts up to 7%. It utilized different sugars, alcohols, hydrocarbons and oil as a carbon source, with preference for sugars. In glucose based minimal medium it produced biosurfactant which reduced surface tension to 29.5 mN/m, interfacial tension to 4.5 mN/m and gave stable emulsion with crude oil and n-hexadecane. The biosurfactant activity was stable at high temperature, a wide range of pH and salt concentrations for five days. Oil displacement experiments using biosurfactant containing broth in sand pack columns with crude oil showed 30.22% recovery. The possible application of organism as biocontrol agent and use of biosurfactant in microbial enhanced oil recovery (MEOR) is discussed.     

Production and Characterization of a Biosurfactant from Cyberlindnera samutprakarnensis JP52T

Cyberlindnera samutprakarnensis JP52^T, isolated from cosmetic industrial wastes in Thailand, was found to be an efficient biosurfactant-producing yeast when cultured in a medium containing (2% (w/v) glucose and 2% (v/v) palm oil at 30 °C, 200 rpm for 7 d. The crude biosurfactant had the ability to reduce the surface tension from 55.7 to 30.9 mN/m at 25 °C with a critical micelle concentration (CMC) of 0.046%. Physicochemical analysis of the crude biosurfactant revealed that it had wide ranges of optimum pH and pH stability at 6–9 and 3–10 respectively. It was also thermostable and retained 80% activity even after heat treatment, and it tolerated NaCl at 1.0–10%. Furthermore, it effectively emulsified various vegetable oils with an E24 value of over 80%. A partially purified biosurfactant fraction was analyzed for its structure by MALDI-TOF MS and NMR. This revealed that the biosurfactant mainly contained sophorolipids in C18-(MW 574) and C16-diaceltylated (MW 662) forms.     

Hydrocarbon Degradation and Biosurfactant Production by an Acenaphthene-degrading Pseudomonas Species

An acenaphthene-degrading bacterium putatively identified as Pseudomonas sp. strain KR3 and isolated from diesel-contaminated soil in Lagos, Nigeria was investigated for its degradative and biosurfactant production potentials on crude oil. Physicochemical analysis of the sampling site indicates gross pollution of the soil with high hydrocarbon content (2100 mg/kg) and detection of various heavy metals. The isolate grew luxuriantly on crude oil, engine oil and acenaphthene. It was resistant to septrin, amoxicillin and augmentin but was susceptible to pefloxacin, streptomycin and gentamycin. It was also resistant to elevated concentration of heavy metals such as 1–15 mM lead, nickel and molybdenum. On acenaphthene, the isolate exhibited specific growth rate and doubling time of 0.098 day^?1 and 3.06 days, respectively. It degraded 62.44% (31.2 mg/l) and 91.78% (45.89 mg/l) of 50 mg/l acenaphthene within 12 and 21 days. On crude oil, the specific growth rate and doubling time were 0.375 day^?1 and 1.85 days with corresponding percentage degradation of 33.01% (903.99 mg/l) and 87.79% (2403.71 mg/l) of crude oil (2738.16 mg/l) within 9 and 18 days. Gas chromatographic analysis of residual crude oil at the end of 18 days incubation showed significant reductions in the aliphatic, alicyclic and aromatic fractions with complete disappearance of benzene, propylbenzene, pristane, phytane, and nC₁₈-octadecane fractions of the crude oil. The isolate produced growth-associated biosurfactant on crude oil with the highest emulsification index (E₂₄) value of 72% ± 0.23 on Day 10 of incubation. The partially purified biosurfactant showed zero tolerance for salinity and had its optimal activity at 27°C and pH 2.0.     

Production and characterization of a glycolipid biosurfactant from Bacillus megaterium using economically cheaper sources

Criteria selected for screening of biosurfactant production by Bacillus megaterium were hemolytic assay, bacterial cell hydrophobicity and the drop-collapse test. The data on hemolytic activity, bacterial cell adherence with crude oil and the drop-collapse test confirmed the biosurfactant-producing ability of the strain. Accordingly, the strain was cultured at different temperatures, pH values, salinity and substrate (crude oil) concentration in mineral salt medium to establish the optimum culture conditions, and it was shown that 38°C, 2.0% of substrate concentration, pH 8.0 and 30‰ of salt concentration were optimal for maximum growth and biosurfactant production. Laboratory scale biosurfactant production in a fermentor was done with crude oil and cheaper carbon sources like waste motor lubricant oil and peanut oil cake, and the highest biosurfactant production was found with peanut oil cake. Characterization of partially purified biosurfactant inferred that it was a glycolipid with emulsification potential of waste motor lubricant oil, crude oil, peanut oil, diesel, kerosene, naphthalene, anthracene and xylene.     

Utilization of renewable agricultural residues for the production of extracellular halostable cellulase from newly isolated Halomonas sp. strain PS47

A newly isolated biopolymer-degrading halophilic bacterium, Halomonas sp. strain PS47, yielded higher cellulase activity (0.0076 U/ml) in mineral salt medium (MM63). Activity increased to 0.029 U/ml when carboxymethyl cellulose (0.5 % w/v) was used as carbon source and further to 0.138 U/ml when a combination of yeast extract and peptone was used as nitrogen source. Enzyme secretion was maximal during late exponential and stationary phases (0.15 U/ml, 48 h). Among different agro-residues (1 % w/v), wheat bran gave the highest activity (0.12 U/ml) at pH 7.5, 30 °C and 6 % (w/v) NaCl. The cellulase exhibited higher activity at pH 7.1 and 50 °C. The enzyme exhibited activity over a wide range of NaCl concentrations (0–4 M). Optimum activity was at 0–1 M NaCl. At 4 M NaCl, activity was reduced to 65 % of the initial value. The present investigation thus contributes to the limited information available on halostable cellulases.     

Optimization,production and characterization of glycolipid biosurfactant from the marine actinobacterium,Streptomyces sp. MAB36

A potential glycolipid biosurfactant producer Streptomyces sp. MAB36 was isolated from marine sediment samples. Medium composition and culture conditions for the glycolipid biosurfactant production by Streptomyces sp. MAB36 were optimized, using two statistical methods: Plackett–Burman design was applied to find out the key ingredients and conditions for the best yield of glycolipid biosurfactant production and central composite design was used to optimize the concentration of the four significant variables, starch, casein, crude oil and incubation time. Fructose and yeast extract were the best carbon and nitrogen sources for the production of the glycolipid biosurfactant. Biochemical characterizations including FTIR and MS studies suggested the glycolipid nature of the biosurfactant. The isolated glycolipid biosurfactant reduced the surface tension of water from 73.2 to 32.4 mN/m. The purified glycolipid biosurfactant showed critical micelle concentrations of 36 mg/l. The glycolipid biosurfactant was effective at very low concentrations over a wide range of temperature, pH, and NaCl concentration. The purified glycolipid biosurfactant showed strong antimicrobial activity. Thus, the strain Streptomyces sp. MAB36 has proved to be a potential source of glycolipid biosurfactant that could be used for the bioremediation processes in the marine environment.     

Characterization and properties of biosurfactants produced by a newly isolated strain <Emphasis Type="Italic">Bacillus methylotrophicus</Emphasis> DCS1 and their applications in enhancing solubility of hydrocarbon

Six biosurfactant-producing bacteria were isolated from hydrocarbon contaminated soils in Sfax, Tunisia. Isolates were screened for biosurfactant production by different conventional methods including hemolytic activity, surface tension reduction, drop-collapsing and oil displacement tests. All these screening tests show that all the isolates behave differently. Among the isolated bacteria, DCS1 strain was selected for further studies based on its highest activities and it was identified as Bacillus methylotrophicus DCS1. This strain was found to be a potent producer of biosurfactant when cultivated in mineral-salts medium supplemented with diesel oil (2 %, v/v) as a sole carbon source. Physicochemical properties and stability of biosurfactants synthesized by B. methylotrophicus DCS1 were investigated. The produced biosurfactants DCS1, from Landy medium, possess high surface activity that could lower the surface tension of water to a value of 31 from 72 mN m^?1 and have a critical micelle concentration (CMC) of 100 mg L^?1. Compared with SDS and Tween 80, biosurfactants showed excellent emulsification activities against different hydrocarbon substrates and high solubilization efficiency towards diesel oil. Biosurfactants DCS1 showed good stability in a wide range of temperature, pH and salinity. These results suggested that biosurfactants produced by B. methylotrophicus DCS1 could be an alternative to chemically synthesized surfactants for use in bioremediation processes to enhance the solubility of hydrophobic compounds.     

Biosurfactant production by a thermophilic Bacillus subtilis strain

A strain of Bacillus subtilis was able to grow and produce a biosurfactant on 2% sucrose at 45°C. As a result of biosurfactant synthesis the surface tension of the medium was reduced from 68 dynes cm⁻¹ to 28 dynes cm⁻¹. The strain had the capacity to produce the biosurfactant at high NaCl concentrations (4%) and a wide range of pH (4.5–10.5). The biosurfactant retained its surface-active properties after heating at 100°C for 2 h and at different pH values (4.5–10.5). A maximum amount of biosurfactant was produced when urea or nitrate ions were supplied as nitrogen source. The use of the biosurfactant at high temperatures, acidic, alkaline and saline environments is discussed. As a result of its action, 62% of oil in a sand pack column could be recovered, indicating its potential application in microbiologically enhanced oil recovery. Received 28 March 1996/ Accepted in revised form 16 September 1996     

An efficient biosurfactant-producing and crude-oil emulsifying bacterium Bacillus methylotrophicus USTBa isolated from petroleum reservoir

An efficient biosurfactant-producing bacterium was isolated and cultured from petroleum reservoir in northeast China. Isolate was screened for biosurfactant production using haemolytic assay, Cetyl Trimethyl Ammonium Bromide agar plate assay (CTAB) and the qualitative oil-displacement test. Based on partial sequenced 16S rDNA analysis of isolate, USTBa, identified as Bacillus methylotrophicus with 100% identity. This bacterium was able to produce a type of biosurfactant with excessive foam-forming properties. The maximum biosurfactant production was obtained when the cells were grown on minimal salt medium containing 2% (v/v) crude-oil as the sole source of carbon at 35 °C and 180 rpm after 192 h. This strain had a high emulsification activity and biosurfactant production of 78% and 1.8 g/L respectively. The cell free broth containing biosurfactant could reduce the surface tension to 28 mN/m. Fourier transform infrared (FT-IR) spectrum of extracted biosurfactant indicates the presence of carboxyl, hydroxyl and methoxyl functional groups. Elemental analysis of the biosurfactant by Energy dispersive X-ray spectroscopy (EDS) reveals that the biosurfactant was anionic in nature. The strain USTBa represented as a potent biosurfactant-producer and could be useful in variety of biotechnological and industrial processes, particularly oil industry.     

Isolation and functional characterization of a biosurfactant produced by a new and promising strain of Oleomonas sagaranensis AT18

Biosurfactant-producing bacteria were isolated from mangrove sediment in southern Thailand. Isolates were screened for biosurfactant production by using the surface tension test. The highest reduction of surface tension was achieved with a bacterial strain which was identified by 16S rRNA gene sequencing as Oleomonas sagaranensis AT18. It has also been investigated using different carbon and nitrogen sources. It showed that the strain was able to grow and reduce the surface tension of the culture supernatant to 25?mN/m. In all 5.30?g of biosurfactant yield was obtained after 54?h of cultivation by using molasses and NaNO(3) as carbon and nitrogen sources, respectively. The biosurfactant recovery by chloroform:methanol extraction showed a small critical micelle concentration value (8?mg/l), thermal and pH stability with respect to surface tension reduction. It also showed emulsification activity and a high level of salt concentration. The biosurfactant obtained was confirmed as a glycolipid by using a biochemical test, FT-IR and mass spectra. The crude biosurfactant showed a broad spectrum of antimicrobial activity and also had the ability to emulsify oil and enhance PAHs solubility.     

Management of soybean oil refinery wastes through recycling them for producing biosurfactant using Pseudomonas aeruginosa MR01

Biosurfactant production through a fermentation process involving the biodegradation of soybean oil refining wastes was studied. Pseudomonas aeruginosa MR01 was able to produce extracellular biosurfactant when it was cultured in three soybean oil refinement wastes; acid oil, deodorizer distillate and soapstock, at different carbon to nitrogen ratios. Subsequent fermentation kinetics in the three types of waste culture were also investigated and compared with kinetic behavior in soybean oil medium. Biodegradation of wastes, biosurfactant production, biomass growth, nitrate consumption and the number of colony forming units were detected in four proposed media, at specified time intervals. Unexpectedly, wastes could stimulate the biodegradation activity of MR01 bacterial cells and thus biosurfactant synthesis beyond that of the refined soybean oil. This is evident from higher yields of biodegradation and production, as revealed in the waste cultures (Y_{deg|(Soybean oil)} = 53.9 % < Y_deg|(wastes) and Y_P/S|(wastes) > Y_{P/S|(Soybean oil)} = 0.31 g g^?1, respectively). Although production yields were approximately the same in the three waste cultures (Y_P/S|(wastes) ? 0.5 g g^?1), microbial activity resulted in higher yields of biodegradation (96.5 ± 1.13 %), maximum specific growth rate (μ _max  = 0.26 ± 0.02 h^?1), and biosurfactant purity (89.6 %) with a productivity of 14.55 ± 1.10 g l^?1, during the bioconversion of soapstock into biosurfactant. Consequently, applying soybean oil soapstock as a substrate for the production of biosurfactant with commercial value has the potential to provide a combination of economical production with environmental protection through the biosynthesis of an environmentally friendly (green) compound and reduction of waste load entering the environment. Moreover, this work inferred spectrophotometry as an easy method to detect rhamnolipids in the biosurfactant products.     

Screening and Evaluation of Biosurfactant-Producing Strains Isolated from Oilfield Wastewater

The six biosurfactant-producing strains, isolated from oilfield wastewater in Daqing oilfield, were screened. The production of biosurfactant was verified by measuring the diameter of the oil spreading, measuring the surface tension value and emulsifying capacity against xylene, n-pentane, kerosene and crude oil. The experimental result showed three strains (S2, S3, S6) had the better surface activity. Among the three strains, the best results were achieved when using S2 strain. The diameter of the oil spreading of the biosurfactant produced by S2 strain was 14 cm, its critical micelle concentration (CMC) was 21.8 mg/l and the interfacial tension between crude oil and biosurfactant solution produced by S2 strain reduced to 25.7 mN/m. The biosurfactant produced by S2 strain was capable of forming stable emulsions with various hydrocarbons, such as xylene, n-pentane, kerosene and crude oil. After S2 strain treatment, the reduction rate of oil viscosity was 51 % and oil freezing point reduced by 4 °C.     

Biosurfactant synthesis by Pseudomonas aeruginosa LBI isolated from a hydrocarbon-contaminated site

Aims: Pseudomonas aeruginosa LBI (Industrial Biotechnology Laboratory) was isolated from hydrocarbon-contaminated soil as a potential producer of biosurfactant and evaluated for hydrocarbon biodegradation. The emulsifying power and stability of the product was assessed in the laboratory, simulating water contamination with benzene, toluene, kerosene, diesel oil and crude oil at various concentrations. Methods and Results: Bacteria were grown at 30°C and shaken at 200 rpm for 168 h, with three repetitions. Surface tension, pH and biosurfactant stability were observed in the cell-free broth after 168 h of incubation. The strain was able to produce biosurfactant and grow in all the carbon sources under study, except benzene and toluene. When cultivated in 30% (w/v) diesel oil, the strain produced the highest quantities (9·9 g l⁻¹) of biosurfactant. The biosurfactant was capable of emulsifying all the hydrocarbons tested. Conclusion: The results from the present study demonstrate that Ps. aeruginosa LBI can grow in diesel oil, kerosene, crude oil and oil sludge and the biosurfactant produced has potential applications in the bioremediation of hydrocarbon-contaminated sites. Significance and Impact of the Study: Pseudomonas aeruginosa LBI or the biosurfactant it produces can be used in the bioremediation of environmental pollution induced by industrial discharge or accidental hydrocarbon spills.     

Isolation and characterization of a biosurfactant‐producing Fusarium sp. BS‐8 from oil contaminated soil

This study reports characterization of a biosurfactant‐producing fungal isolate from oil contaminated soil of Missa Keswal oil field, Pakistan. It was identified as Fusarium sp. BS‐8 on the basis of macroscopic and microscopic morphology, and 18S rDNA gene sequence homology. The biosurfactant‐producing capability of the fungal isolates was screened using oil displacement activity, emulsification index assay, and surface tension (SFT) measurement. The optimization of operational parameters and culture conditions resulted in maximum biosurfactant production using 9% (v/v) inoculum at 30°C, pH 7.0, using sucrose and yeast extract, as carbon and nitrogen sources, respectively. A C:N ratio of 0.9:0.1 (w/w) was found to be optimum for growth and biosurfactant production. At optimal conditions, it attained lowest SFT (i.e., 32 mN m^?1) with a critical micelle concentration of ≥ 1.2 mg mL^?1. During 5 L shake flask fermentation experiments, the biosurfactant productivity was 1.21 g L^?1 pure biosurfactant having significant emulsifying index (E₂₄, 70%) and oil‐displacing activity (16 mm). Thin layer chromatography and Fourier transform infrared spectrometric analyses indicated a lipopeptide type of the biosurfactant. The Fusarium sp. BS‐8 has substantial potential of biosurfactant production, yet it needs to be fully characterized with possibility of relatively new class of biosurfactants. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1065–1075, 2014     

Biosurfactant production and growth kinetics of bacteria in a designer marine medium: improved physiochemical properties

A combinatorial screening strategy was adopted for the development of a suitable medium for enhanced biosurfactant production by a marine strain. As a result, a modified marine medium (MMM) was developed, which contained urea and strontium chloride besides other salts important for the growth of marine bacteria. This medium supported growth, evident from a higher maximum growth rate value of 0.42 h(-1) and an enhanced biosurfactant production of 2.58 g/L. The critical micelle concentration (CMC) was determined for the biosurfactants obtained from all tested media combinations. The biosurfactant produced with this medium was stable at high temperature (100 °C), a wide range of pH (5-11) and salt concentration of 5-35%. The emulsifying activity and stability of the biosurfactant obtained using MMM was better than the biosurfactant obtained using conventional media. This biosurfactant with improved physiochemical properties is suitable for a wide range of applications in industry and for marine environmental cleaning.     

Application of Biosurfactants Produced by Pseudomonas aeruginosa SP4 for Bioremediation of Soils Contaminated by Pyrene

Biosurfactants are considered to facilitate PAHs dissolution in soil slurries for bioremediation applications. In this work, the carbon and nitrogen sources, pH, C/N ratio, and salinity, were considered for optimization of biosurfactant production by Pseudomonas aeruginosa SP4 isolate to enhance pyrene removal from the contaminated soil. Analysis of ANOVA indicated that the carbon source was the most effective factor, followed by pH, nitrogen source, C/N ratio, and salinity. Taguchi experimental design proposed the optimum operating conditions of olive oil, NH₄NO₃, C/N ratio of 5, salinity of 0.5%, and pH 7. Applying the conditions determined by Taguchi design led to a production yield of 452 mg L^?1 (13% improvement) at the optimum conditions. The main characteristics of produced biosurfactant included the critical micelle concentration (CMC) of 60 mg L^?1 and liquid medium surface tension of 29.5 mN m^?1. Produced biosurfactant was used for bioremediation of soil artificially contaminated with 500 mg kg^?1 of pyrene. Following the addition of 250 mg L^?1 biosurfactant, the pyrene removal of 84.6% was obtained compared to 59.8% for control sample without any surfactant.