Acinetobacter haemolyticus MG606 produces a novel, phosphate binding exobiopolymer

The present study evaluated an extracellular, novel biopolymer produced by Acinetobacter haemolyticus MG606 for its physicochemical properties and phosphate binding mechanism. The exobiopolymer (EBP) was characterized to be majorly polysaccharide in nature consisting of 48.9 kDa heteropolysaccharide composed of galactose, glucose, xylose, lyxose, allose, ribose, arabinose, mannose and fructose. Maximum phosphate binding efficiency of 25 mg phosphate/g of EBP was described by Langmuir isotherm and further, the physicochemical and spectroscopic studies revealed that phosphate appeared to bind predominantly with the polysaccharide fraction, and to a relatively lesser extent to protein fraction of EBP. The electrostatic interactions with amino groups and ligand exchange with hydroxyl groups of EBP were found to be primary basis for phosphate binding mechanism. The results of this study implicate the feasibility of the EBP for commercial bioremediation processes.