Biosurfactant production and diesel oil degradation by yeast species trichosporon asahii isolated from petroleum hydrocarbon contaminated soil

TLDR: The yeast Trichosporon asahii, isolated from petroleum-contaminated soil in India was found to be the potent producer of biosurfactant in mineral salt media containing diesel oil as the carbon source and an efficient degrader of diesel oil over a period of 10 days.

Abstract: The yeast Trichosporon asahii, isolated from petroleum-contaminated soil in India was found to be the potent producer of biosurfactant in mineral salt media containing diesel oil as the carbon source and found to be an efficient degrader of diesel oil (95%) over a period of 10 days. The crude biosurfactant was purified using silica gel column chromatography followed by dialysis .With the use of FTIR spectroscopy, in combination with GC-MS analysis, chemical structures of the purified biosurfactant was identified as sophorolipid species. When compared to synthetic surfactants, including Tween 80 and sodium dodecyl sulfate, the biosurfactant showed high physicochemical properties in terms of the surface activities. Involvement of biosurfactant in physiological mechanism of diesel adsorption on yeast cell surface was characterized based on zeta potential measurement. When diesel oil was emulsified with biosurfactant, the surface charge of the diesel was modified resulting more adsorption of diesel on yeast cell surface. Biosurfactant production by yeast species was monitored using SEM analysis.