γ-聚谷氨酸产生菌BLN-2的分离鉴定及固体发酵条件初探

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

摘要:

从豆制品中分离得到一株γ-聚谷氨酸(γ-PGA)产生菌BLN-2, 通过对BLN-2的生理生化和16S rRNA系统发育特征进行分析鉴定, 明确该菌株为枯草芽孢杆菌。以黄豆为基本培养物, 对BLN-2的固体发酵条件进行了初步探索, 结果表明, 葡萄糖、果糖和NaNO3、KNO3分别为BLN-2的较适碳、氮源。正交试验结果表明, 当向黄豆中添加的果糖终浓度为0.5%, 葡萄糖、NaNO3及KNO3终浓度均为2.0%时, γ-PGA产量最高, 为89.05 g/kg, 比相同条件下基本对照黄豆培养物的产量(60 g/kg)高48.42%。

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.