a b s t r a c t
Marine endosymbiotic fungi Aspergillus ustus (MSF3) which produce high yield of biosurfactant was
isolated from the marine sponge Fasciospongia cavernosa collected from the peninsular coast of India.
Maximum production of biosurfactantwas obtained in Sabouraud dextrose broth. The optimized bioprocess
conditions for themaximumproductionwas pH7.0, temperature 20 ◦C, salt concentration 3%, glucose
and yeast extract as carbon source and nitrogen sources respectively. The response surface methodology
based analysis of carbon and nitrogen ratio revealed that the carbon source can increase the biosurfactant
yield. The biosurfactant produced by MSF3 was partially characterized as glycolipoprotein based on
the estimation of macromolecules and TLC analysis. The partially purified biosurfactant showed broad
spectrum of antimicrobial activity. The strain MSF3 can be used for the microbially enhanced oil recovery
process.