Improved production, characterization and flocculation properties of poly ()-glutamic acid produced from Bacillus Subtilis

Bacillus subtilis 2063 produced extracellular biopolymer whichshowed excellent flocculation activity. The biopolymer wasconfirmed as poly (γ-glutamic acid) (PGA) by using productcharacterization. HPLC profile showed that molecular weight ofPGA was found to be 5.8×106 Da. Improved production,Characterization and flocculation properties of PGA produced byBacillus species were studied. PGA produced by B. subtilis wasdevoid of any polysaccharides. The flocculating activity wasmarkedly stimulated by the addition of cations. The pH of reaction mixture also influenced the flocculating activity. Glycerol and ammonium chloride were found to be most useful carbon and nitrogen sources. An overall 4.24-fold increase in protease production was achieved in the design medium composed with Glycerol and ammonium chloride as a carbon and nitrogen sources as compared with basal media. PGA production increased significantly with optimized medium (21.42 gl-1) when compared with basal medium (5.06 gl-1).