Isolation and Identification of BLN-2 Producing Poly-γ-Glutamic Acid and Studies on Its Solid-state Fermentation

Abstract:

A poly-γ-glutamic acid producing strain--BLN-2, was isolated from the soybean products. According to the biochemical characteristics and 16S rRNA, the strain was identified as Bacillus subtilis. Using soybeans as culture, the solid-state fermentation conditions of BLN-2 have been studied. The results showed that the optimal carbon and nitrogen sources of BLN-2 were glucose, fructose, NaNO3 and KNO3, respectively. The orthrogonal experiments showed, when the final concentration of the fructose which was added to the soybean culture was 0.5%, the glucose, NaNO3 and KNO3 final concentraion were 2.0%, the production of γ-PGA was the highest--89.05 g/kg. It is 48.42% higher than other comparable soybean medium under the same conditions.