ROLES OF N-ACETYLGLUTAMINYLGLUTAMINE AMIDE AND GLYCINE BETAINE IN ADAPTATION OF PSEUDOMONAS-AERUGINOSA TO OSMOTIC-STRESS
ROLES OF N-ACETYLGLUTAMINYLGLUTAMINE AMIDE AND GLYCINE BETAINE IN ADAPTATION OF PSEUDOMONAS-AERUGINOSA TO OSMOTIC-STRESS
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DOI：
10.1128/aem.59.2.473-478.1993
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发表时间：
1993-02-01
影响因子：
4.4
通讯作者：
SMITH, GM
中科院分区：
文献类型：
--
作者：
DSOUZAAULT, MR;SMITH, LT;SMITH, GM
对铜绿假单胞菌PAO1的渗透胁迫适应机制进行了研究。通过使用自然丰度的C-13核磁共振波谱，发现渗透胁迫培养物积累了谷氨酸、海藻糖和N-乙酰谷氨酰谷氨酰胺，这是一种以前只在渗透胁迫下报道的紫花苜蓿根瘤菌和荧光假单胞菌中报道的不寻常的二肽。这些渗透剂的细胞内水平取决于生长介质的化学成分和渗透压。甘氨酸甜菜碱是一种强大的渗透胁迫保护剂，参与了该生物的渗透调节。当添加甘氨酸甜菜碱或其前体磷胆碱或胆碱时，在0.7M的氯化钠中培养物的生长速度提高了3倍以上。此外，在培养基中加入少量的甘氨酸甜菜碱或前体即可促进生长。最后，两株铜绿假单胞菌临床分离株的渗透胁迫适应机制与实验室分离株PAO1的渗透胁迫适应机制基本一致。
The mechanism of osmotic stress adaptation in Pseudomonas aeruginosa PAO1 was investigated. By using natural abundance C-13 nuclear magnetic resonance spectroscopy, osmotically stressed cultures were found to accumulate glutamate, trehalose, and N-acetylglutaminylglutamine amide, an unusual dipeptide previously reported only in osmotically stressed Rhizobium meliloti and Pseudomonas fluorescens. The intracellular levels of these osmolytes were dependent on the chemical composition and the osmolality of the growth medium. It was also demonstrated that glycine betaine, a powerful osmotic stress protectant, participates in osmoregulation in this organism. When glycine betaine or its precursors, phosphorylcholine or choline, were added to the growth medium, growth rates of cultures in 0.7 M NaCl were increased more than threefold. Furthermore, enhancement of growth could be observed with as little as 10 muM glycine betaine or precursor added to the medium. Finally, the mechanism of osmotic stress adaptation of two clinical isolates of P. aeruginosa was found to be nearly identical to that of the laboratory strain PAO1 in all aspects studied.