植物乳杆菌Lp-G18谷氨酰胺合成酶活力发酵工艺优化

Optimization of Fermentation Medium for Production of Glutamine Synthetase by Lactobacillus plantarum Lp-G18

植物乳杆菌是一种具有多种生物活性的益生菌,其中缓解肌肉疲劳和损伤能力的运动保健功能引起了市场的关注,这与其谷氨酰胺合成酶(glutamine synthetase,GS)的活力相关,目前尚缺乏对植物乳杆菌GS发酵工艺研究的报道。通过在培养基中添加L-谷氨酸、调整碳源以及改变金属离子质量浓度等方式提高植物乳杆菌Lp-G18发酵后的GS活力。得到优化培养基组成为:葡萄糖40 g/L(222 mmol/L)、七水硫酸镁4.92 g/L(20 mmol/L)、一水硫酸锰0.025 g/L、L-谷氨酸8.82 g/L(60 mmol/L)、蛋白胨10 g/L、牛肉浸粉10 g/L、酵母膏5 g/L、磷酸氢二钾2 g/L、柠檬酸氢二胺2 g/L、乙酸钠5 g/L、吐温-80 1 g/L。采用优化培养基发酵得到的GS活力比原基础MRS培养基培养条件下的酶活力提高了1.4倍。

Lactobacillus plantarum is a probiotic bacterium with various biological effects.Its ability to relieve muscle fatigue and injury has aroused market concerns,which is associated with glutamine synthetase(GS)activity.However,the literature currently lacks reports on the production of GS by fermentation with Lactobacillus plantarum.In this study,the GS activity of L.plantarum Lp-G18 was enhanced by adding L-glutamic acid to the medium and optimizing the carbon sources and metal ion concentrations.The optimized medium was composed of glucose 40 g/L(222 mmol/L),MgSO4·7H2O 4.92 g/L(20 mmol/L),MnSO4 0.025 g/L(1.5 mmol/L),L-glutamic acid 8.82 g/L(60 mmol/L),peptone 10 g/L,beef extract powder 10 g/L,yeast extract powder 5 g/L,K2HPO4 2 g/L,NaAc 5 g/L,diammonium hydrogen citrate 2 g/L,and Tween-801 g/L.The GS activity obtained using the optimized medium was 2.4 times higher than that from basal MRS medium.