Surface-active potential of biosurfactants produced in curd whey by Pseudomonas aeruginosa strain-PP2 and Kocuria turfanesis strain-J at extreme environmental conditions.

Surface-active potential of biosurfactants produced cost-effectively in curd whey by Pseudomonas aeruginosa strain-PP2 and Kocuria turfanesis strain-J were tested using parameters viz. surface tension (ST) reduction, F(CMC) (highest dilution factor to reach critical micelle concentration) and emulsification index (EI-24) of pesticides; monocrotophos and imidacloprid at extreme environmental conditions. Results have shown that ST reduction of biosurfactants was stable at pH 2-11. High F(CMC) of the biosurfactant in the fermented whey at low pH improved emulsification of pesticides. ST marginally increased at 5% and 15% NaCl, resulting in high EI-24 and F(CMC). Over a range of temperatures 30-121 °C, ST remained low with a higher F(CMC) and EI-24 at 60 °C than at 121 and 30 °C. The biosurfactants have shown differences in their surface-active property and have marked specificity to emulsify pesticides in extreme environmental conditions.