一株不需谷氨酸的产聚γ-谷氨酸菌株的筛选与鉴定

Screening and Identification of an Independent-glutamic Acid Strain Producing Poly(γ-glutamic acid)

摘要:

从豆制品中分离得到17株不依赖谷氨酸作为发酵底物的γ-PGA生产菌株，分别以氨盐和葡萄糖作为氮源和碳源的培养基进行好氧发酵，并测定发酵液中PGA的含量，对其中一株PGA高产菌株PGA-O-7进行了形态、生理生化和遗传学研究，结果表明PGA-O-7为枯草芽孢杆菌(Bacillus subtilis)。在以葡萄糖为碳源、硫酸铵为氮源的发酵培养基中，30℃振荡培养3d，PGA产量可达到2.8mg/mL。

关键词:聚谷氨酸(γ-PGA)，筛选，鉴定，枯草芽孢杆菌(Bacillus subtilis)

Abstract:

17 strains of bacterium that produced a large amount of γ-PGA when it was grown aerobically in a culture medium containing ammonium salt and sugar as sources of nitrogen and carbon respectively，were isolated from bean products.With the following identifications of colony morphology，physiological and biochemistry experiments，and genetics，the strain PGA-O-7 was classified as a Bacillus subtilis.The PGA production 2.8 (mg/mL) was obtained when it was grown in a medium containing 3% ammonium sulfate and 4% glucose at 30℃ for 72h with sharking.

Key words:Poly(γ-glutamic acid) [γ-PGA]，Screening，Identification，Bacillus subtilis