Synthesis, Characterization, and Oil Recovery Application of Biosurfactant Produced by Indigenous Pseudomonas aeruginosa WJ-1 Using Waste Vegetable Oils

• Published in: Applied biochemistry and biotechnology Vol. 166; no. 5; pp. 1148 - 1166
• Main Authors: Xia, Wen-Jie, Luo, Zhi-bin, Dong, Han-Ping, Yu, Li, Cui, Qing-Feng, Bi, Yong-Qiang
• Format: Journal Article
• Language: English
• Published: New York Humana Press Inc 01-03-2012; Springer Nature B.V
• Subjects: Biochemistry; Biosynthesis; Biotechnology; Chemical synthesis; Chemistry; Chemistry and Materials Science; Excavation; Extracellular Space - metabolism; Fourier transforms; Glycolipids - chemistry; Glycolipids - isolation & purification; Glycolipids - metabolism; Hydrogen-Ion Concentration; Industrial Waste; Metals - chemistry; Micelles; Oil recovery; Plant Oils - chemistry; Plant Oils - metabolism; Pseudomonas aeruginosa; Pseudomonas aeruginosa - cytology; Pseudomonas aeruginosa - isolation & purification; Pseudomonas aeruginosa - metabolism; Salinity; Surface tension; Surface-Active Agents - chemistry; Surface-Active Agents - isolation & purification; Surface-Active Agents - metabolism; Surfactants; Temperature; Thin layer chromatography; Vegetable oils; Waste materials; Biosurfactant; Surface tension; Rhamnolipid; Oil recovery; Emulsification
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-011-9501-y

A bacterial strain was isolated and cultured from the oil excavation areas in tropical zone in northern China. The biochemical characteristics and partial sequenced 16S rRNA gene of isolate, WJ-1, was identical to those of cultured representatives of the species
Pseudomonas aeruginosa
. This bacterium was able to produce a type of biosurfactant. Compositional analysis revealed that the extracted biosurfactant was composed of high percentage lipid (∼74%,
w
/
w
) and carbohydrate (∼20%,
w
/
w
) in addition to a minor fraction of protein (∼6%,
w
/
w
). The best production of 50.2 g/l was obtained when the cells were grown on minimal salt medium containing 6.0% (
w
/
v
) glucose and 0.75% (
w
/
v
) sodium nitrate supplemented with 0.1% (
v
/
v
) element solution at 37 °C and 180 rpm after 96 h. The optimum biosurfactant production pH value was found to be 6.0–8.0. The biosurfactant of WJ-1, with the critical micelle concentration of 0.014 g/L, could reduce surface tension to 24.5 mN/m and emulsified kerosene up to EI
24
≈95. The results obtained from time course study indicated that the surface tension reduction and emulsification potential was increased in the same way to cell growth. However, maximum biosurfactant production occurred and established in the stationary growth phase (after 90 h). Thin layer chromatography, Fourier transform infrared spectrum, and mass spectrum analysis indicate the extracted biosurfactant was affiliated with rhamnolipid. The core holder flooding experiments demonstrated that the oil recovery efficiency of strain and its biosurfactant was 23.02% residual oil.