植物乳杆菌降解亚硝酸盐及其亚硝酸盐还原酶的研究

摘要

对一株分离自泡菜的植物乳杆菌进行了亚硝酸盐降解的相关研究.首先研究了培养条件对植物乳杆菌降解亚硝酸盐的影响,结果表明:该菌降解亚硝酸盐的最适培养温度为30 ℃,最适碳源为葡萄糖,最适氮源为酵母抽提物,而在MRS培养基中降解亚硝酸盐能力最强.随后对该菌的亚硝酸盐还原酶进行了提取纯化和酶学性质研究,结果表明:该植物乳杆菌的亚硝酸盐还原酶可能为细胞色素cdI型,分子量大小约为123.2 kDa;其最适反应温度为35 ℃,最适pH值为6.5,Km值为30.0 mmol/L;Cu2+和Mn2+为该酶的激活剂,而Zn2+,K+,EDTA为该酶的抑制剂.%The research on nitrite degradation of a strain of L.plantarum isolated from kimchi is carried out.Firstly, the culture conditions for nitrite degradation are studied.The results show that the optimum culture temperature for nitrite degradation is 30 ℃, the optimum carbon source is glucose and the optimum nitrogen source is yeast extract, and it shows the strongest ability to nitrite degradation in MRS medium.Subsequently, the nitrite reductase is extracted and purified.The results show that the nitrite reductase of L.plantarum may be cytochrome cdI type with the molecular weight of about 123.2 kDa.The optimum reaction temperature is 35 ℃, the optimum pH value is 6.5 and the Km value is 30.0 mmol/L.Cu2+ and Mn2+ are activators, and Zn2+, K+ and EDTA are inhibitors for the nitrite reductase.