Production, characterization and emulsifying property of exopolysaccharide produced by marine isolate of Pseudomonas fluorescens

Most of the natural emulsifiers are obtained from pig fat and rarely from oils like palm oil and coconut oil. Hence, an attempt has been made to isolate and identify the bacteria capable of producing exopolysaccharides which can serve as good emulsifier and can be used in the preparation of safe creams and lotions. Pseudomonas fluorescens isolated from the biofilm formed on catamaran was found to synthesize 2.9 mg/ml of exopolysaccharide. Box Behnken Optimization method predicted the maximum EPS production of 2.86 mg/ml with sucrose, yeast extract, calcium chloride and casamino acid concentration of 2.5, 0.35, 0.35 and 0.75 g/l respectively. FTIR analysis of the extracted polymer showed the presence of protein which might have helped in the formation of stable emulsion. HPLC report indicated the presence glucose, fructose, galactose, rhamnose and mannose and NMR analysis confirmed the presence of glucose, galactose and mannose. The GC analysis identified palmitic, myristic and stearic acid in the EPS. The emulsification activity was almost found to be similar in hydrocarbon with fatty acid compared to hydrocarbon without fatty acid. This ability qualifies P. fluorescens as a potential candidate for bioremediation processes and the EPS produced as a substitute for synthetic emulsifiers.