Characterization of a novel biosurfactant produced by Staphylococcus sp. strain 1E with potential application on hydrocarbon bioremediation.

A biosurfactant-producing bacterium (Staphylococcus sp. strain 1E) was isolated from an Algerian crude oil contaminated soil. Biosurfactant production was tested with different carbon sources using the surface tension measurement and the oil displacement test. Olive oil produced the highest reduction in surface tension (25.9 dynes cm(-1)). Crude oil presented the best substrate for 1E biosurfactant emulsification activity. The biosurfactant produced by strain 1E reduced the growth medium surface tension below 30 dynes cm(-1). This reduction was also obtained in cell-free filtrates. Biosurfactant produced by strain 1E showed stability in a wide range of pH (from 2 to 12), temperature (from 4 to 55 °C) and salinity (from 0 to 300 g l(-1)) variations. The biosurfactant produced by strain 1E belonged to lipopeptide group and also constituted an antibacterial activity againt the pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. Phenanthrene solubility in water was enhanced by biosurfactant addition. Our results suggest that the 1E biosurfactant has interesting properties for its application in bioremediation of hydrocarbons contaminated sites.

Eddouaouda K ，Mnif S ，Badis A ，Younes SB ，Cherif S ，Ferhat S ，Mhiri N ，Chamkha M ，Sayadi S ... -  《-》

Optimization of environmental factors for improved production of rhamnolipid biosurfactant by Pseudomonas aeruginosa RS29 on glycerol.

A biosurfactant producing Pseudomonas aeruginosa RS29 (identified on the basis of 16S rDNA analysis) with good foaming and emulsification properties has been isolated from crude oil contaminated sites. Optimization of different environmental factors was carried out with an objective to achieve maximum production of biosurfactant. Production of biosurfactant was estimated in terms of surface tension reduction and emulsification (E24) index. It was recorded that the isolated strain produced highest biosurfactant after 48 h of incubation at 37.5 °C, with a pH range of 7-8 and at salinity <0.8% (w/v). Ammonium nitrate used in the experiment was the best nitrogen source for the growth of biomass of P. aeruginosa RS29. On the other hand sodium and potassium nitrate enhanced the production of biosurfactant (Surface tension, 26.3 and 26.4 mN/m and E24 index, 80 and 79% respectively). The CMC of the biosurfactant was 90 mg/l. Maximum biomass (6.30 g/l) and biosurfactant production (0.80 g/l) were recorded at an optimal C/N ratio of 12.5. Biochemical analysis and FTIR spectra confirmed that the biosurfactant was rhamnolipid in nature. GC-MS analysis revealed the presence of C(8) and C(10) fatty acid components in the purified biosurfactant.

Saikia RR ，Deka S ，Deka M ，Sarma H ... -  《-》

Diversity of biosurfactant producing microorganisms isolated from soils contaminated with diesel oil.

Menezes Bento F ，de Oliveira Camargo FA ，Okeke BC ，Frankenberger WT Jr ... -  《-》

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

Pirôllo MP ，Mariano AP ，Lovaglio RB ，Costa SG ，Walter V ，Hausmann R ，Contiero J ... -  《-》

Isolation and characterization of Halomonas sp. strain C2SS100, a hydrocarbon-degrading bacterium under hypersaline conditions.

Mnif S ，Chamkha M ，Sayadi S 《-》