Biosurfactant from lowcost substrates synthesis characterization physiochemical studies and applications

Abstract

The microbial surface active agents or biosurfactant have shown potential in various applications because of their specific surface action, very low toxicity, good emulsifying capacity and also utilized as wetting agent, spreading agent, foaming agent in detergent, food processing, cosmetics, fertilizers and widespread in various field like medical industries, petroleum and petrochemicals. Biosurfactants have unique properties like low toxicity, biodegradability and biocompatibility. Biosurfactants are microbial products produced via fermentative procedure with a suitable microbial strain like Pseudomonas aeruginosa and utilizing a low priced by-product or waste materials as substrate. newline newlineIn one investigation the kinetics of transesterification of three waste cooking (vegetable) oils viz waste soybean oil, waste groundnut oil and waste sunflower oil with methanol were studied using KOH as catalyst. Transesterification of fatty acids generate fatty acid esters (biodiesel) and glycerol. The emphasis was given to the production of glycerol due to its high commercial value (may be utilized as raw material for variety of other valuable products). The transesterification reaction was found to be second order when concentration of methanol was limited. The effect of temperature on the conversion of glycerol was studied and rate constant were determined for all three waste cooking (vegetable) oils. The maximum conversion was achieved at 60°C in all cases. Upon comparison of values of % conversion of glycerol, rate constant and activation energy for the reaction, waste soybean oil transesterification was found to be better among all three waste vegetable oils studied with the 70% conversion to glycerol, higher rate constant and lower value of activation energy for their action. newlineIn another study the optimization of process parameters (C/N ratio, temperature and pH) for the production of biosurfactant using Pseudomonas aeruginosa MTCC 7814 was investigated. The statistical tool viz. CCD-RSM was used for analyzing the optimum