一株干酪乳杆菌对养殖水体亚硝酸盐去除机理的研究

The study of nitrite degradation mechanism by a strain Lactobacillus casei in aquaculture water

为了解乳酸菌去除养殖水体亚硝酸盐的作用机理,实验研究了一株干酪乳杆菌L821a(Lactobacillus casei)对淡水鱼养殖水体亚硝酸盐的去除状况,通过对菌体、酶及代谢产物的实验,证明其去除亚硝酸盐的机理包括胞内酶作用、代谢产物乳酸的直接化学反应2H++3NO2-=NO3-+2NO↑+H2O作用和间接促进微生物反硝化作用3种作用机理。在养殖水体中主要以间接作用方式发挥作用。分析认为乳酸促进反硝化作用的原因在于为反硝化微生物提供了易于利用的有机碳源(能量物质)。

In order to understand the nitrite degradation mechanism by lactic acid bacteria in the aquaculture water, the study explored the nitrite degradation by a strain Lactobacillus casei L821 a in the process of freshwater fish breeding accord-ing to the analyses of cell, enzyme and metabolin, and proved that the nitrite degradation involves three different modes, namely intracellular enzymolysis, direct chemical reaction of 2H^＋ ＋3NO2^-=NO3^-＋2NO↑＋H2O of lactic acid and indi- rect effect of promoting microbial denitrification. The latter one was the mainly effect in the aquaculture water. Further a- nalysis also showed that the reason of denitrification promotion by lactic acid was that it provides the easy - to - use organic carbon （energy material） for denitrifying bacteria.