Abstract:
In the present study, the production and characterization of biosurfactant from yeast Pichia anomala strain PY189 were investigated. The highest efficiency for biosurfactant production was found when the organism was grown in modified medium with soybean oil 4%, as carbon source and NaNO3 0.4%, as nitrogen source using optimal condition at 30ºC, pH of 5.5 for 7 days. After 7 days of cultivation, P. anomala PY189 was able to produce biosurfactant up to 0.57 gL⁻¹. The crude biosurfactant was able to reduce the surface tension of pure water to 36.5 mN/m, oil displacement activity of 10.17 cm² with a critical micelle concentration (CMC) of 204 mg/l, it exhibited HLB value of 10-13. Result from TLC analysis indicated that crude biosurfactant consisted of 4 major bands with Rf values of 0.92, 0.81, 0.76 and 0.55 (F1-F4), respectively. Among these, F3 gave highest oil displacement activity and gave positive test with sugar. Further, F3 was fractionated via HPLC in combination with MALDI-TOF MS, the chemical structure of the most relatively abundant fraction was identified as sophorolipid in nature. This biosurfactant can be used as emulsifier for lemomgrass oil. Emulsion containing biosurfactant concentration at 0.8 and 1% was stable and having particle size less than 10µm. Lemongrass oil emulsion was prepared for microencapsulation using spray dry technique. Microencapsulation efficiency was 48.5 and 51.6% at lemongrass oil:maltodextrin ratio 0.2:1 and 0.15:1, respectively. This microcapsule also exhibited microbial inhibition activity against E.coli, S. aureus and Salmonella sp.