An investigation on the production of rhamnolipid biosurfactant by Pseudomonas aeruginosa MAL01

Production of a glycolipide type of biosurfactant from Pseudomonas aeruginosa MAL01 isolated from oil refinary soil is reported here. This biosurfactant is able to reduce the surface tension of water from 72 to about 28 mN/m with an increase of the biosurfactant concentration up to critical micelle concentration (CMC) value of about 50 mg/l. The analysis of the extracted biosurfactant by thin-layer chromatography and infrared spectroscopy confirmed the chemical structure of a glycolipid-type biosurfactant. The strain produced biosurfactant much higher in the medium containing sunflower oil compared to the media with other carbon sources. The production of biosurfactant was parallel to the cell growth and primary yield of biosurfactant using this strain was about 5 g/L. The produced biosurfactant was relatively thermo-stable and no appreciable changes in biosurfactant activity occurred at temperature ranges of 20-100C. The biosurfactant maintained its stability in pH range of 5 -10 and salinity of 0-30%w.

کلیدواژه ها:

Pseudomonas aeruginosa ، Biosurfactant ، Characterization