高渗环境对枯草芽孢杆菌和粘质沙雷氏菌胞内自由氨基酸库含量和组成的影响

INFLUENCE OF HIGH OSMOTIC ENVIRONMENT ON THE CONTENT AND COMPOSITION OF FREE AMINO ACID POOLS IN BACILLUS SUBTILUS AND SERRATIA MARCESENS

在基本培养基中９６ｈ培养下，４％ＮａＣｌ可完全抑制粘质沙雷氏菌（ＡＢ９００２５）生长，而枯草芽孢杆菌（９３１５１和９３２１５）则可耐受高达８％ＮａＣｌ．与无ＮａＣｌ条件下相比，粘质沙雷氏菌在２％ＮａＣｌ浓度下，胞内谷氨酸、丙氨酸和苯丙氨酸含量分别增加６１５％，１３５７％和１２７０％，为该菌的主要渗透调节物质．枯草芽孢杆菌在无ＮａＣｌ条件下，胞内未测出脯氨酸，而在８％ＮａＣｌ浓度下脯氨酸成为胞内含量最高的氨基酸，在每克干细胞中含量高达３３．３ｍｇ，是枯草芽孢杆菌体内合成的主要相容溶质．

The growth of Serratia marcescens (AB90025) was completely inhibited by 4% NaCl incubated in minimal medium for 96 hours, and the contents of glutamine, alanine and phenylalanine in cells increased 615%, 157% and 1270% in 2% NaCl medium compared with the one without NaCl, respectively. But Bacillus subtilus (93151 and 93215) can grow in 8% NaCl minimal medium for 96 hours. Under the condition without NaCl, no proline was detected in the cells. When the external NaCl concentration was increased to 8%, proline increased to 33.3 mg·g -1 dry cell and was the highest content amino acid in the cells. These results indicate that glutamine, alanine and phenylalanine are the main osmotic regulation solutes in Serratia marcescens, and proline is the main compatible solute in Bacillus subtilus.