Abstract:A γ-polyglutamicacid (γ-PGA) producing strain (JPND618) was isolated using streaked plate method. The strain was identified through strain morphological, physiological-biochemical characteristics and sequence contrastive analysis of 16S rRNA. The fermenting product was identified, and its water absorption property, scale property, flocculation property and biodegradable property were studied. The results showed that, the physiological-biochemical characteristics of strain JPND618 were similar to bacillus genus, and the homelogy of 16S rDNA sequence with Bacillus amyloliquefaciens NBRC 15535 reached 98%, thus strain JPND618 was identified as Bacillus amyloliquefaciens. The yield of γ-PGA was 4.86 g/L. γ-PGA showed much better water absorption and biodegradable property than Polyacrylamide (PAM), and similar water-retaining property with PAM. The anti scale rates towards CaSO4, CaCO3 reached more than 70%, and flocculation towards Gaolin suspension was good. γ-PGA produced by strain JPND618 was proved as a kind of environmental friendly biological materials with high performance, which has a better application prospect. This study supplies a new strain for producing γ-PGA.
