The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological technique...The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.展开更多
Biosurfactant,produced by Pseudomonas aeruginosa BSZ-07,was added to the dee straw decomposing process to enhance the production of reducing sugars.Observed by Fourier Transform InfraRed(FT-IR)and Nuclear Magnetic Res...Biosurfactant,produced by Pseudomonas aeruginosa BSZ-07,was added to the dee straw decomposing process to enhance the production of reducing sugars.Observed by Fourier Transform InfraRed(FT-IR)and Nuclear Magnetic Resonance(NMR)analysis, the purified biosurfactant was considered as a mixture of RL1 and RL2,which are two different types of rhamnolipids.Two different adding methods,adding the purified rhamnolipid and the on-site production of it were compared.The results showed that 0.5 g/L was the optimum...展开更多
Objective:To characterize the pharmacological importance of biosurfactants isolated from halophilic Bacillus sp BS3.Methods:Halophilic Bacillus sp.BS3 was isolated from solar salt works,identified by 16S rRNA sequenci...Objective:To characterize the pharmacological importance of biosurfactants isolated from halophilic Bacillus sp BS3.Methods:Halophilic Bacillus sp.BS3 was isolated from solar salt works,identified by 16S rRNA sequencing and was used for screening their biosurfactant production.Characters of the biosurfactant and their anticancer activity were analyzed and performed in mammary epithelial carcinoma cell at different concentrations.Results:The biosurfactant were characterized by TLC,FTIR and GC-MS analysis and identified as lipopeptide type.GC-MS analysis revealed that,the biosurfactant had various compounds including 13Docosenamide.(Z);Mannosamine,9- and N,N,N',N'-tetramethyl.Surprisingly the antiviral activity was found against shrimp white spot syndrome virus(WSSV) by suppressing the viral replication and significantly raised shrimp survival(P<0.01).Anticancer activity performed in the mammary epithelial carcinoma cell at different concentrations of biosurfactants,among the various concentrations of biosurfactants such as 0.000 25,0.002 5,0.025,0.25 and 2.5 μ g,the 0.25 μ g concentration suppressed the cells significantly(P<0.05) to 24.8%.Conclusions:Based on the findings,the present study concluded that,there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.展开更多
Biosurfactants are biomolecules produced by microorganisms, which possess several advantages over their chemical counterparts. Production can be cost-effective if renewable wastes are utilized as substrates. In this s...Biosurfactants are biomolecules produced by microorganisms, which possess several advantages over their chemical counterparts. Production can be cost-effective if renewable wastes are utilized as substrates. In this study, optimization of biosurfactant production by <i>Pseudomonas aeruginosa</i> strain CGA1 was carried out using response surface methodology. The conventional “One factor at a time” method of optimization was initially adopted to ascertain the impact of different renewable wastes on biosurfactant production. Four independent variables were tested: carbon and nitrogen concentration, medium volume, and inoculum size. Biosurfactant production was based on the emulsification index measurement. Results indicated that the preferred carbon source by the isolate was sugar cane molasses. A 2.31-fold increase in biosurfactant yield and emulsification index of 96.3% ± 0.75% under optimized cultural conditions of 20 g/L of molasses, 5 g/L of sodium nitrate, 1.93 ml inoculum size and 60 ml medium volume in 250 ml conical flask were obtained. The regression coefficient (R<sup>2</sup>) value of 84.15% implied adequate fitness of the model. The surface tension of distilled water was reduced from 72.1 mN/m to 35.0 ± 0.0 mN/m, and critical micelle concentration was attained at 60 mg·L<sup>-1</sup>. FTIR and GC-MS analysis indicated that the biosurfactant was a lipopeptide having characteristic lipid and peptide peak values. This study proves that the sole use of agro-industrial wastes for the production of biosurfactant is very efficient, and ensures the economic feasibility of biosurfactant production.展开更多
Bacillus subtilis was investigated as production of biosurfactant using a combination based on waste of candy industry and glycerol from biodiesel production process as only substrate. The experimental design chosen f...Bacillus subtilis was investigated as production of biosurfactant using a combination based on waste of candy industry and glycerol from biodiesel production process as only substrate. The experimental design chosen for optimization by response surface methodology was a central composite rotatable design (CCRD) and dry weight (DW) and crude biosurfactant (CB) concentrations were selected as responses in analysis. Two techniques were implemented response surface methodology (RSM) and artificial neural network (ANN). First challenge of study was to assess the effects of the interactions between variables and reach optimum values. With the CCRD results, RSM and ANN models were developed, optimizing the production of biosurfactant. The correlation coefficients (R2) of RSM models explained 88% for DW and 73% for CB of the interactions among substrate concentrations, while ANN models explained 99% for DW and 98% for CB, demonstrating that developed ANN models were more accurate and consistent in predicting optimized conditions than RSM model. The maximum DW and CB produced in the optimum conditions were 25.60 ± 5.0 g/L and 668 ± 40 mg/L, respectively. The crude biosurfactant also showed applications in cases of oil spreading in water due to clear zone produced in Petri dishes assays.展开更多
Activity of a crude biosurfactant extracted from the culture fluid of Serratia sp. that was isolated from riverbed soil was shown to increase in proportion to the cultivation time, and was higher at pH 8 than at pH 7....Activity of a crude biosurfactant extracted from the culture fluid of Serratia sp. that was isolated from riverbed soil was shown to increase in proportion to the cultivation time, and was higher at pH 8 than at pH 7. Serratia sp. grew in the mineral-based medium with soybean oil but was not with kerosene-diesel. The petroleum-degrading bacteria—Acinetobacter sp., Pseudomonas sp., Paracoccus sp., and Cupriavidus sp.—were isolated from a specially designed enrichment culture. The efficiency of mineralization of wastewater contaminated with kerosene and diesel (WKD) by the petroleum-degrading bacterial community (PDBC) was enhanced significantly by addition of the crude biosurfactant. The efficiency of mineralization of the WKD was also about 2 times boosted by co-culture of Serratia sp. and PDBC. Bacterial community of Serratia sp. and PDBC co-cultivated in the WKD was maintained for at least 8 days according to the TGGE pattern of 16S rDNA obtained from the bacterial culture. In conclusion, the co-culture of Serratia sp. and PDBC is an applicable technique for the mineralization of wastewater contaminated with petroleum, which may substitute for chemical or biological surfactant.展开更多
Fermented beverages have continued to give more surprises in terms of the presence of biomolecules and the diversity of microorganisms that may be contained. Republic of Congo is home to a panoply of fermented foods a...Fermented beverages have continued to give more surprises in terms of the presence of biomolecules and the diversity of microorganisms that may be contained. Republic of Congo is home to a panoply of fermented foods and beverages that are still not yet studied. This is the case of plantain wine fluently called banana wine. Within this framework, this work aims to study the role of Biosurfactant-like Biomolecules secreted during fermentation of plantain wine. Using MRS medium, 15 isolates bacteria have been found. 100% are able to secrete biosurfactant and 66.66% are extractible biosurfactants. 33% of isolates have been associated to Lactobacillus plantarum (Is2, Is9, Is12 and Is13) by using a one-step multi-plex PCR that targets genes encoding for bacteriocins. Biosurfactants secreted by L. plantarum play an important role in the preservation of banana wine. The biosurfactants extracted with chloroform and ammonium sulphate are able to inhibit the growth of pathogenic bacteria including Shigella flexneri, Salmonella spp., Pseudomonas aeruginosa and Staphy-lococcus aureus.展开更多
Infection and intoxication are two common types of foodborne illnesses throughout the world.The aim of the present work was to isolate and characterize biosurfactant producing bacteria fromgroundnut oil cake dumping s...Infection and intoxication are two common types of foodborne illnesses throughout the world.The aim of the present work was to isolate and characterize biosurfactant producing bacteria fromgroundnut oil cake dumping sites and evaluate their biocontrol effects against foodborne pathogens.Bacteria were isolated by enrichment culture technique and preliminary screening method.Biosurfactant activity evaluation was carried out by oil displacement,drop collapse test,lipase activity,hemolytic activity,emulsification index and emulsification assay methods.16s rRNA sequence analysis was used for the isolate identification.Crude biosurfactant was extracted by acid precipitation method and characterized using FTIR(Fourier Transform Infrared Spectroscopy).Antibacterial activity was investigated using disc diffusion method.CMCand surface reduction were analyzed by DuNouy tensiometer.Top 10 strains were selected for biosurfactant activity assessment from the total 30 isolates.In addition,16s rRNA sequence identified that the potential isolate was Bacillus pseudomycoides OR 1.Then,FTIR result of the extracted biosurfactant established the extract as a lipopeptide based on the absorption peaks at 3500 to 3200 cm^-1 and 2963 to 2854.68 cm^-1,respectively.50μg/mL of lipopeptide showed the highest antibacterial activity.Critical Micelle Concentration(CMC)of the lipopeptide was 60 mg/L and it reduced the surface tension of water from 71.6 to 31.6 mN/m.Hence,this study widens the scope to employ the bacterial lipopeptide surfactant as a promising biocontrol agent against foodborne pathogens.展开更多
We investigated the ability of a bacterial community constructed with six strains isolated from an oily sludge, to utilize diesel oil at high concentrations. The consortium was able to grow at concentrations up to 84 ...We investigated the ability of a bacterial community constructed with six strains isolated from an oily sludge, to utilize diesel oil at high concentrations. The consortium was able to grow at concentrations up to 84 g diesel oil/L and had produced biosurfactants during its active growth phase;these compounds, in their crude form, reduced the surface tension of distilled water from 72 mN/m to 31 mN/m, with a corresponding Critical Micelle Concentration value γCMC = 81 mg/L. The plot of specific growth rates obtained from the growth curves versus initial concentrations was found to fit adequately the experimental data by the Andrews inhibitory model, which resulted in the following kinetic constants: μmax = 0.535d-1 ± 0.063, KS = 18.68 g/L ± 3.59 and KI = 29.02 g/L ± 4.96, reflecting the slow biodegradation rate. At 25.2 g diesel oil/L, close to the optimal concentration S* = 23.28 g/L ± 4.23, the consortium metabolized diesel oil faster than each strain did individually, suggesting that the process was stimulated by a synergistic interaction between the members of the consortium.展开更多
There were six high diesel oil degrading bacteria strains isolated fro m the oil contaminated soil that collected from Linzi City. The strain Y1 was ab le to produce biosurfactant rhamnolipid when cultivated on diesel...There were six high diesel oil degrading bacteria strains isolated fro m the oil contaminated soil that collected from Linzi City. The strain Y1 was ab le to produce biosurfactant rhamnolipid when cultivated on diesel oil as carbon source. The critical micelle concentrations (CMC) of rhamnolipid in water and in the soil were measured respectively according to the correlation between the su rface tension of the medium and the added rhamnolipid concentration. The results showed that the CMC of rhamnolipid in water was 65 mg/L, and was 185 mg/L in so il. The tests on diesel oil biodegradation were conducted with the addition of d ifferent concentrations of rhamnolipid in water and in soil respectively. When 0 .01% rhamnolipid was added to water, the diesel oil degradation was enhanced. On the contrary, when the same concentration of rhamnolipid was added to the soil, the degradation of diesel oil was inhibited. The results suggested that the rha mnolipid could enhance the diesel oil biodegradation, indicating that the concen tration of rhamnolipid was higher than the corresponding CMC in the medium. Kine tics parameters for the diesel oil biodegradation parameters such as biodegradat ion constant (λ), coefficient of correlation(r) and half life (t1/2) in both t ests were numerically analyzed in this paper, indicating that the moderate conc entration of rhamnolipid in the medium could not only enhance the extent of dies el oil biodegradation but also shorten the time for oil remediation.展开更多
The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene (PHE) onto the original or H2O2-treated black loamy soil (typic isohumisols) and red sandy soil (typic ferralisols...The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene (PHE) onto the original or H2O2-treated black loamy soil (typic isohumisols) and red sandy soil (typic ferralisols). The sorption isotherms were performed with the original and "soft" carbon-removed soils in the presence and absence of biosurfactant (200 mg/L). The sorption and degradation of biosurfactant were investigated. The result showed that organic matter played an important role in PHE sorption onto the black loamy and red sandy soils, and the PHE sorption isotherms on the "soft" carbon-removed soils exhibited more nonlinearity than those on the original soils. The values of partition coeffcient (Kd) on the original black loamy soil with or without 200 mg/L biosurfactant were 181.6 and 494.5 mL/g, respectively. Correspondingly, in the red sandy soil, Kd was 246.4 and 212.8 mL/g in the presence or absence of biosurfactant, respectively. The changes of Kd suggested that biosurfactant inhibited PHE sorption onto the black loamy soil, but facilitated PHE sorption onto the red sandy soil. The nonlinearity of PHE sorption isotherm was decreased in the presence of biosurfactant. Site specific sorption might occur during PHE sorption onto both the original and the "soft" carbon-removed soils in the presence of biosurfactant. It was noted that biosurfactant could also be sorbed onto soils. The maximal sorption capacity of the red sandy soil for biosurfactant was (76.9 ± 0.007) μg/g, which was 1.31 times that of black loamy soil. Biosurfactant was degraded quickly in the two selected soils, and 92% of biosurfactant were mineralized throughout the incubation experiment for 7 d. It implied that biosurfactant should be added frequently when the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils was conducted through PAH desorption approach facilitated by biosurfactant.展开更多
The production and properties of the biosurfactant synthesized by Bacillus subtilis CCTCC AB93108 were studied. The maximum concentration of the surfactant is 1.64 g/L when the bacteria grow in a medium supplemented w...The production and properties of the biosurfactant synthesized by Bacillus subtilis CCTCC AB93108 were studied. The maximum concentration of the surfactant is 1.64 g/L when the bacteria grow in a medium supplemented with glucose as carbon sources. The isolated biosurfactant is a complex of protein and polysaccharide without lipids. It reduces the surface tension of distilled water to 45.9 mN/m, and its critical micelle concentration (CMC) is 2.96 g/L. It can stabilize emulsions of several aromatic and aliphatic hydrocarbons, such as benzene, xylene, n-pentane, n-nonane, gasoline and diesel oil. It presents high emulsification activity and stability in a wide range of temperature (4-100 ℃) and a long period of duration.展开更多
A Bacillus subtilis strain JA-1 isolated from an oil reservoir was studied.This strain is capable of growth and producing biosurfactant at a temperature of 60 oC.In nutrient medium it produced biosurfactant which redu...A Bacillus subtilis strain JA-1 isolated from an oil reservoir was studied.This strain is capable of growth and producing biosurfactant at a temperature of 60 oC.In nutrient medium it produced biosurfactant which reduced the surface tension from 68.2 mN/m to 28.3 mN/m,with the critical micelle concentration (CMC) of 48 mg/L.The measured surface tension indicated that the biosurfactant possessed stable surface activity at high temperature and a specific range of pH and salt concentrations.The results of thin layer chromatography (TLC) together with FT-IR showed that the metabolic product of strain JA-1 is a lipopeptide biosurfactant.The ability to growth at high temperature and to produce biosurfactant makes strain JA-1 promising for enhanced oil recovery.展开更多
After incubation for 6- 30 h,with the rapid increase of bacterial cell number,surface tension of bacterium BS-8 was reduced sharply from 63. 2 m N / m to 39. 4 m N / m. The production of biosurfactants by BS-8 was gro...After incubation for 6- 30 h,with the rapid increase of bacterial cell number,surface tension of bacterium BS-8 was reduced sharply from 63. 2 m N / m to 39. 4 m N / m. The production of biosurfactants by BS-8 was growth-dependent. Using glucose as the carbon source,bacterium BS-8 was incubated. Based on centrifugation,precipitation and chromogenic reaction of the culture solution,results indicated that the biosurfactants belonged to lipopeptides. The yield of biosurfactants isolated and purified from the culture solution was 0. 58 g / L,and the critical micelle concentration( CMC) was 90 mg / L. Under conditions of p H 4- 9,temperature 20- 70 ℃,Na Cl concentration 1%- 6%,biosurfactants produced by BS-8 exhibited the highest stability.展开更多
Biosurfactants are biologically active metabolites,and the efficiency of direct screening of new biosurfactants from nature using traditional methods is low,which should be enhanced in the following studies by adoptin...Biosurfactants are biologically active metabolites,and the efficiency of direct screening of new biosurfactants from nature using traditional methods is low,which should be enhanced in the following studies by adopting advanced biotechnologies. Rapid development and wide application of microbial culture independent methods,such as metagenomics,metatranscriptomics,metaproteomics and metabonomics,etc.,contributes to quickly and precisely screening of novel biological surfactants. We mainly represented the current status of research and applications of biosurfactants in the remediation of petrochemical polluted environment,and also prospected avenues for future research.展开更多
文摘The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.
文摘Biosurfactant,produced by Pseudomonas aeruginosa BSZ-07,was added to the dee straw decomposing process to enhance the production of reducing sugars.Observed by Fourier Transform InfraRed(FT-IR)and Nuclear Magnetic Resonance(NMR)analysis, the purified biosurfactant was considered as a mixture of RL1 and RL2,which are two different types of rhamnolipids.Two different adding methods,adding the purified rhamnolipid and the on-site production of it were compared.The results showed that 0.5 g/L was the optimum...
基金The work was supported by Tamil Nadu State Council for Science and Technology(TNSCST),Chennai,India(MS-004/TNSCST/SPS/AR/2010-2011)
文摘Objective:To characterize the pharmacological importance of biosurfactants isolated from halophilic Bacillus sp BS3.Methods:Halophilic Bacillus sp.BS3 was isolated from solar salt works,identified by 16S rRNA sequencing and was used for screening their biosurfactant production.Characters of the biosurfactant and their anticancer activity were analyzed and performed in mammary epithelial carcinoma cell at different concentrations.Results:The biosurfactant were characterized by TLC,FTIR and GC-MS analysis and identified as lipopeptide type.GC-MS analysis revealed that,the biosurfactant had various compounds including 13Docosenamide.(Z);Mannosamine,9- and N,N,N',N'-tetramethyl.Surprisingly the antiviral activity was found against shrimp white spot syndrome virus(WSSV) by suppressing the viral replication and significantly raised shrimp survival(P<0.01).Anticancer activity performed in the mammary epithelial carcinoma cell at different concentrations of biosurfactants,among the various concentrations of biosurfactants such as 0.000 25,0.002 5,0.025,0.25 and 2.5 μ g,the 0.25 μ g concentration suppressed the cells significantly(P<0.05) to 24.8%.Conclusions:Based on the findings,the present study concluded that,there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.
文摘Biosurfactants are biomolecules produced by microorganisms, which possess several advantages over their chemical counterparts. Production can be cost-effective if renewable wastes are utilized as substrates. In this study, optimization of biosurfactant production by <i>Pseudomonas aeruginosa</i> strain CGA1 was carried out using response surface methodology. The conventional “One factor at a time” method of optimization was initially adopted to ascertain the impact of different renewable wastes on biosurfactant production. Four independent variables were tested: carbon and nitrogen concentration, medium volume, and inoculum size. Biosurfactant production was based on the emulsification index measurement. Results indicated that the preferred carbon source by the isolate was sugar cane molasses. A 2.31-fold increase in biosurfactant yield and emulsification index of 96.3% ± 0.75% under optimized cultural conditions of 20 g/L of molasses, 5 g/L of sodium nitrate, 1.93 ml inoculum size and 60 ml medium volume in 250 ml conical flask were obtained. The regression coefficient (R<sup>2</sup>) value of 84.15% implied adequate fitness of the model. The surface tension of distilled water was reduced from 72.1 mN/m to 35.0 ± 0.0 mN/m, and critical micelle concentration was attained at 60 mg·L<sup>-1</sup>. FTIR and GC-MS analysis indicated that the biosurfactant was a lipopeptide having characteristic lipid and peptide peak values. This study proves that the sole use of agro-industrial wastes for the production of biosurfactant is very efficient, and ensures the economic feasibility of biosurfactant production.
文摘Bacillus subtilis was investigated as production of biosurfactant using a combination based on waste of candy industry and glycerol from biodiesel production process as only substrate. The experimental design chosen for optimization by response surface methodology was a central composite rotatable design (CCRD) and dry weight (DW) and crude biosurfactant (CB) concentrations were selected as responses in analysis. Two techniques were implemented response surface methodology (RSM) and artificial neural network (ANN). First challenge of study was to assess the effects of the interactions between variables and reach optimum values. With the CCRD results, RSM and ANN models were developed, optimizing the production of biosurfactant. The correlation coefficients (R2) of RSM models explained 88% for DW and 73% for CB of the interactions among substrate concentrations, while ANN models explained 99% for DW and 98% for CB, demonstrating that developed ANN models were more accurate and consistent in predicting optimized conditions than RSM model. The maximum DW and CB produced in the optimum conditions were 25.60 ± 5.0 g/L and 668 ± 40 mg/L, respectively. The crude biosurfactant also showed applications in cases of oil spreading in water due to clear zone produced in Petri dishes assays.
文摘Activity of a crude biosurfactant extracted from the culture fluid of Serratia sp. that was isolated from riverbed soil was shown to increase in proportion to the cultivation time, and was higher at pH 8 than at pH 7. Serratia sp. grew in the mineral-based medium with soybean oil but was not with kerosene-diesel. The petroleum-degrading bacteria—Acinetobacter sp., Pseudomonas sp., Paracoccus sp., and Cupriavidus sp.—were isolated from a specially designed enrichment culture. The efficiency of mineralization of wastewater contaminated with kerosene and diesel (WKD) by the petroleum-degrading bacterial community (PDBC) was enhanced significantly by addition of the crude biosurfactant. The efficiency of mineralization of the WKD was also about 2 times boosted by co-culture of Serratia sp. and PDBC. Bacterial community of Serratia sp. and PDBC co-cultivated in the WKD was maintained for at least 8 days according to the TGGE pattern of 16S rDNA obtained from the bacterial culture. In conclusion, the co-culture of Serratia sp. and PDBC is an applicable technique for the mineralization of wastewater contaminated with petroleum, which may substitute for chemical or biological surfactant.
文摘Fermented beverages have continued to give more surprises in terms of the presence of biomolecules and the diversity of microorganisms that may be contained. Republic of Congo is home to a panoply of fermented foods and beverages that are still not yet studied. This is the case of plantain wine fluently called banana wine. Within this framework, this work aims to study the role of Biosurfactant-like Biomolecules secreted during fermentation of plantain wine. Using MRS medium, 15 isolates bacteria have been found. 100% are able to secrete biosurfactant and 66.66% are extractible biosurfactants. 33% of isolates have been associated to Lactobacillus plantarum (Is2, Is9, Is12 and Is13) by using a one-step multi-plex PCR that targets genes encoding for bacteriocins. Biosurfactants secreted by L. plantarum play an important role in the preservation of banana wine. The biosurfactants extracted with chloroform and ammonium sulphate are able to inhibit the growth of pathogenic bacteria including Shigella flexneri, Salmonella spp., Pseudomonas aeruginosa and Staphy-lococcus aureus.
文摘Infection and intoxication are two common types of foodborne illnesses throughout the world.The aim of the present work was to isolate and characterize biosurfactant producing bacteria fromgroundnut oil cake dumping sites and evaluate their biocontrol effects against foodborne pathogens.Bacteria were isolated by enrichment culture technique and preliminary screening method.Biosurfactant activity evaluation was carried out by oil displacement,drop collapse test,lipase activity,hemolytic activity,emulsification index and emulsification assay methods.16s rRNA sequence analysis was used for the isolate identification.Crude biosurfactant was extracted by acid precipitation method and characterized using FTIR(Fourier Transform Infrared Spectroscopy).Antibacterial activity was investigated using disc diffusion method.CMCand surface reduction were analyzed by DuNouy tensiometer.Top 10 strains were selected for biosurfactant activity assessment from the total 30 isolates.In addition,16s rRNA sequence identified that the potential isolate was Bacillus pseudomycoides OR 1.Then,FTIR result of the extracted biosurfactant established the extract as a lipopeptide based on the absorption peaks at 3500 to 3200 cm^-1 and 2963 to 2854.68 cm^-1,respectively.50μg/mL of lipopeptide showed the highest antibacterial activity.Critical Micelle Concentration(CMC)of the lipopeptide was 60 mg/L and it reduced the surface tension of water from 71.6 to 31.6 mN/m.Hence,this study widens the scope to employ the bacterial lipopeptide surfactant as a promising biocontrol agent against foodborne pathogens.
文摘We investigated the ability of a bacterial community constructed with six strains isolated from an oily sludge, to utilize diesel oil at high concentrations. The consortium was able to grow at concentrations up to 84 g diesel oil/L and had produced biosurfactants during its active growth phase;these compounds, in their crude form, reduced the surface tension of distilled water from 72 mN/m to 31 mN/m, with a corresponding Critical Micelle Concentration value γCMC = 81 mg/L. The plot of specific growth rates obtained from the growth curves versus initial concentrations was found to fit adequately the experimental data by the Andrews inhibitory model, which resulted in the following kinetic constants: μmax = 0.535d-1 ± 0.063, KS = 18.68 g/L ± 3.59 and KI = 29.02 g/L ± 4.96, reflecting the slow biodegradation rate. At 25.2 g diesel oil/L, close to the optimal concentration S* = 23.28 g/L ± 4.23, the consortium metabolized diesel oil faster than each strain did individually, suggesting that the process was stimulated by a synergistic interaction between the members of the consortium.
基金The National Natural Science Foundation of China (No. 40272108) and the Doctor Subject Foundation of the Ministry of Educationof China (No. 20040423016)
文摘There were six high diesel oil degrading bacteria strains isolated fro m the oil contaminated soil that collected from Linzi City. The strain Y1 was ab le to produce biosurfactant rhamnolipid when cultivated on diesel oil as carbon source. The critical micelle concentrations (CMC) of rhamnolipid in water and in the soil were measured respectively according to the correlation between the su rface tension of the medium and the added rhamnolipid concentration. The results showed that the CMC of rhamnolipid in water was 65 mg/L, and was 185 mg/L in so il. The tests on diesel oil biodegradation were conducted with the addition of d ifferent concentrations of rhamnolipid in water and in soil respectively. When 0 .01% rhamnolipid was added to water, the diesel oil degradation was enhanced. On the contrary, when the same concentration of rhamnolipid was added to the soil, the degradation of diesel oil was inhibited. The results suggested that the rha mnolipid could enhance the diesel oil biodegradation, indicating that the concen tration of rhamnolipid was higher than the corresponding CMC in the medium. Kine tics parameters for the diesel oil biodegradation parameters such as biodegradat ion constant (λ), coefficient of correlation(r) and half life (t1/2) in both t ests were numerically analyzed in this paper, indicating that the moderate conc entration of rhamnolipid in the medium could not only enhance the extent of dies el oil biodegradation but also shorten the time for oil remediation.
基金supported by the National Hi-Tech Research and Development Program (863) of China (No2007AA061101)the National Natural Scientific Foun-dation of China (No 20377024)
文摘The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene (PHE) onto the original or H2O2-treated black loamy soil (typic isohumisols) and red sandy soil (typic ferralisols). The sorption isotherms were performed with the original and "soft" carbon-removed soils in the presence and absence of biosurfactant (200 mg/L). The sorption and degradation of biosurfactant were investigated. The result showed that organic matter played an important role in PHE sorption onto the black loamy and red sandy soils, and the PHE sorption isotherms on the "soft" carbon-removed soils exhibited more nonlinearity than those on the original soils. The values of partition coeffcient (Kd) on the original black loamy soil with or without 200 mg/L biosurfactant were 181.6 and 494.5 mL/g, respectively. Correspondingly, in the red sandy soil, Kd was 246.4 and 212.8 mL/g in the presence or absence of biosurfactant, respectively. The changes of Kd suggested that biosurfactant inhibited PHE sorption onto the black loamy soil, but facilitated PHE sorption onto the red sandy soil. The nonlinearity of PHE sorption isotherm was decreased in the presence of biosurfactant. Site specific sorption might occur during PHE sorption onto both the original and the "soft" carbon-removed soils in the presence of biosurfactant. It was noted that biosurfactant could also be sorbed onto soils. The maximal sorption capacity of the red sandy soil for biosurfactant was (76.9 ± 0.007) μg/g, which was 1.31 times that of black loamy soil. Biosurfactant was degraded quickly in the two selected soils, and 92% of biosurfactant were mineralized throughout the incubation experiment for 7 d. It implied that biosurfactant should be added frequently when the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils was conducted through PAH desorption approach facilitated by biosurfactant.
基金Project(IRT0719) supported by the Program for Changjiang Scholars and Innovative Research Team in University of China Project (2004AA649370) supported by the National High-Tech Research and Development Program of China+1 种基金 Projects(50425927, 50225926) supported by the Natural Foundation for Distinguished Young Scholars Project(2007F3102) supported by Technology Foundation for Creative Young Scholars of Fujian Province, China
文摘The production and properties of the biosurfactant synthesized by Bacillus subtilis CCTCC AB93108 were studied. The maximum concentration of the surfactant is 1.64 g/L when the bacteria grow in a medium supplemented with glucose as carbon sources. The isolated biosurfactant is a complex of protein and polysaccharide without lipids. It reduces the surface tension of distilled water to 45.9 mN/m, and its critical micelle concentration (CMC) is 2.96 g/L. It can stabilize emulsions of several aromatic and aliphatic hydrocarbons, such as benzene, xylene, n-pentane, n-nonane, gasoline and diesel oil. It presents high emulsification activity and stability in a wide range of temperature (4-100 ℃) and a long period of duration.
基金supported by the National High-technology Research and Development Program(863Program)of China(Grant No.2009AA063504)China National Petroleum Corporation Science&Technology Management Program(2008A-1403)
文摘A Bacillus subtilis strain JA-1 isolated from an oil reservoir was studied.This strain is capable of growth and producing biosurfactant at a temperature of 60 oC.In nutrient medium it produced biosurfactant which reduced the surface tension from 68.2 mN/m to 28.3 mN/m,with the critical micelle concentration (CMC) of 48 mg/L.The measured surface tension indicated that the biosurfactant possessed stable surface activity at high temperature and a specific range of pH and salt concentrations.The results of thin layer chromatography (TLC) together with FT-IR showed that the metabolic product of strain JA-1 is a lipopeptide biosurfactant.The ability to growth at high temperature and to produce biosurfactant makes strain JA-1 promising for enhanced oil recovery.
基金Supported by Key Science and Technology Program of Henan Province(132102310253,122102310350)Natural Science Research Program of Education Department of Henan Province(15A210020,12A180008)
文摘After incubation for 6- 30 h,with the rapid increase of bacterial cell number,surface tension of bacterium BS-8 was reduced sharply from 63. 2 m N / m to 39. 4 m N / m. The production of biosurfactants by BS-8 was growth-dependent. Using glucose as the carbon source,bacterium BS-8 was incubated. Based on centrifugation,precipitation and chromogenic reaction of the culture solution,results indicated that the biosurfactants belonged to lipopeptides. The yield of biosurfactants isolated and purified from the culture solution was 0. 58 g / L,and the critical micelle concentration( CMC) was 90 mg / L. Under conditions of p H 4- 9,temperature 20- 70 ℃,Na Cl concentration 1%- 6%,biosurfactants produced by BS-8 exhibited the highest stability.
文摘Biosurfactants are biologically active metabolites,and the efficiency of direct screening of new biosurfactants from nature using traditional methods is low,which should be enhanced in the following studies by adopting advanced biotechnologies. Rapid development and wide application of microbial culture independent methods,such as metagenomics,metatranscriptomics,metaproteomics and metabonomics,etc.,contributes to quickly and precisely screening of novel biological surfactants. We mainly represented the current status of research and applications of biosurfactants in the remediation of petrochemical polluted environment,and also prospected avenues for future research.
