Optimisation of Rhamnolipid: A New Age Biosurfactant from Pseudomonas aeruginosa MTCC 1688 and its Application in Oil Recovery, Heavy and Toxic Metals Recovery

摘要

Rhamnolipid is a new age biosurfactant, commonly produced biotechnologically with Pseudomonas aeruginosa in batch cultivations whereas novel substrates like karanja oil and soybean oil cake were employed, giving yield of 3.609 gm/lit of rhamnolipid, which shows effective and enhanced production of rhamnolipid, compared to other vegetable oil as a carbon sources, mentioned in the literature, at optimised pH of 7.0 and optimised substrate concentration at 3.0%. The optimum yield in terms of substrate was observed as 3.609 gm/lit of rhamnolipid produced per 5.255 ml of oil consumed, while yield in terms of biomass was observed as 3.609 gm/lit of rhamnolipid produced per 2.5 gm of dry biomass. The chloroform:methanol (2:1) extraction system was found to be the best solvent extraction system, where 83% of the rhamnolipid was recovered. The Rhamnolipid was successfully applied for the heavy and toxic metals recovery, where rhamnolipid reduces heavy metal concentration to 73%, 65% and 71% for FeCl3, ZnSO4 and Pb(NO3)2 respectively, while 43% in the case of toxic metal i.e. NaF. The produced rhamnolipid was found efficient in recovering 31% no-edible oil from oil sludge.