为了研究植物乳杆菌(Lactobacillus plantarum)L5降解亚硝酸盐的机理,采用盐酸萘乙二胺法、十二烷基硫酸钠聚丙烯酰胺凝胶电泳和扫描电镜分别对亚硝酸盐存在条件下L5的降解亚硝酸盐能力、蛋白的表达和菌体形态等进行了初步研究。结果表明,在正常培养条件下,发酵36 h,L5对亚硝酸盐的降解率为56.25%;在控制p H 6.8,消除酸对亚硝酸盐降解作用的条件下,发酵36 h,L5对亚硝酸盐的降解率为70.59%;在有亚硝酸盐存在的条件下,L5能分泌一种分子质量约为200 k Da的a蛋白,且分子质量为50 k Da左右的b蛋白、分子质量为40 k Da左右的c蛋白、分子质量为34 k Da左右的d蛋白的表达均上调;L5在以亚硝酸盐为唯一氮源的培养基中仍然能生长,但亚硝酸盐的存在使L5的菌体形态发生了改变。

In order to study nitrite degradation mechanism of Lactobacillus plantarum L5,its ability to degrade nitrite,protein expression and bacteria morphology in the presence of nitrite were studied using N-( 1-naphthyl) ethylenediamine dihydrochloride method,sodium dodecyl sulfate polyacrylamide gel electrophoresis,and scanning electron microscope respectively. Results showed that the nitrite degradation rate was 56. 25% after fermentation under normal conditions for 36 h. When the p H value was retained at 6. 8 and the acid degradation was eliminated,the nitrite degradation rate was 70. 59%. In the presence of nitrite,L5 could secrete protein A with molecular weight about 200 k Da. Furthermore,expressions of protein B with molecular weight about 50 k Da,protein C with molecular weight about 40 k Da,protein D with molecular weight about 34 k Da were all improved. L5 could still grow in the culture medium with nitrite as the only nitrogen source,but the existence of nitrite changed its shape.