屎肠球菌JT1701对人体肠系细菌的调控作用

用屎肠球菌JT1701与人体肠系有害菌（大肠杆菌、产气荚膜梭菌、脆弱拟杆菌）和人体肠系益生菌（婴儿双歧杆菌、嗜酸乳杆菌）分别及共同培养发现，肠球球菌对这些菌均有抑制作用。它能抑制这些菌氨的产生，降低培养基的pH。其原因是，屎肠球菌与氨产生相关的尿酶、氨基酸脱氨酶的种类少，酶活性亦低，而与NH4^ 同化相关的谷氨酸脱氢酶、谷氨酸合酶、谷酰氨合成酶的活性要高得多。表明屎肠球菌对人体肠系菌群具有调控作用。

Regulatory Effects of Enterococcus Faecium JT1701 on Intestinal Bacteria of Humans

The inhibitory effects of human derived Enterococcus faecium JT1701 on harmful intestinal bacteria were examined by co cultivation of JT1701 with each one of the following three harmful bacterial strains: Escherichia Coli, Clostridium perfringens and Bacteroides fragilis and two benefical bacterial strains: Bifidobacteria infantis and Lactobacillus acidophilus. The regulatory effects of Enterococcus faecium JT1701 on human intestinal bacteria were examined by mix cultivation of JT1701 with the above mentioned five strins. In comparison with the results of mono cultivation, JT1701 inhibited both the growth of these bacteria and their production of ammonia, and decresed the pH of the culture medium by producing lactic and acetic acids, balanced with the intestinal bacteria. Enzymatic assays showed that in E.faecium JT1701, the sorts of the enzymes involved in ammonia production (Urease and ammino acid deaminases) were rather few and their activities were weaker than those observed in the other strains, whereas the activities of enzymes involved in ammonia assimilation (glutamine synthetase, glutamate synthase and glutamate dehydrogenase) were much higher in E.faecium JT1701 than in the other bacteria.