高产γ-氨基丁酸植物乳杆菌的微波诱变育种

Selection of high-yield γ-aminobotyric acid-producing Lactobacillus plantarum by microwave mutagenesis

目的利用微波辐照对植物乳酸杆菌进行诱变育种,筛选高产γ-氨基丁酸的正突变菌株。方法以TYG为发酵培养基,37.0℃培养48 h后,测定微波诱变后的植物乳杆菌产γ-氨基丁酸的量。结果诱变后突变菌株W_(462)S_5的γ-氨基丁酸的产量为9.18 g/L,相比于未诱变前的产量(4.64 g/L),提高了97.84%。对正突变菌株W_(462)S_5进行8次传代培养发酵,测得γ-氨基丁酸的产量较为稳定,表明W_(462)S_5是一株遗传性状稳定的正突变菌株。结论微波诱变菌株不仅有操作简单、设备常见、实验条件易于控制等优点,且选育出的菌株具有培养周期短、易于分离纯化、遗传性状稳定等优势。将此方法应用于发酵γ-氨基丁酸生产中,具有一定的研究意义。

Objective To screen a positive mutant strain with high-yield γ-aminobotyric acid by mutagenesis of Lactobacillus plantarum using microwave irradiation. Methods Using TYG as fermentation medium, L. plantarumwas fermented at 37.0 ℃ for 48 h, then the yield of γ-aminobotyric acid of L. plantarum was determined after microwave mutagenesis. Results According to the method, compared to the pre mutagenic yield of 4.64 g/L, the content of γ-aminobotyric acid by positive mutant strain of W_（462）S_5 was 9.18 g/L, which increased by 97.84%. After 8 generations of subculture fermentation of W_（462）S_5, the content of γ-aminobotyric acid was relatively stable. The results showed that W_（462）S_5 was an excellent genetic stable mutant strain. Conclusion The microwave mutation strains have the advantages of simple operation, common equipments and easy control of the experimental conditions, and the selected strain has the advantages of short culture period, easy separation and purification, and stable genetic characteristics and so on. The application of this method in the production of γ-aminobotyric acid has certain research significance.