Mikkat S, Galinski E A, Berg G, Minkwitz A, Schoor A
Universität Rostock, FB Biologie, Germany.
Syst Appl Microbiol. 2000 Apr;23(1):31-40. doi: 10.1016/S0723-2020(00)80043-0.
The compatible solute glucosylglycerol (GG) is widespread among cyanobacteria, but, until now, has been reported for only two species of heterotrophic bacteria. About 120 bacterial isolates from coastal regions of the Baltic Sea were screened by HPLC for their ability to synthesize GG. Positive isolates (26) were grouped by SDS-PAGE of whole-cell proteins and representative strains of each group were investigated by sequencing their 16S rRNA genes and phenotypic characterization. All GG-synthesizing isolates were shown to belong to the genus Pseudomonas (sensu stricto) and were assigned to 4 distinct groups, although none of the GG-synthesizing isolates could be unambiguously assigned to described species. The identity of GG was verified by 13C NMR analysis and enzymatic digestion with alpha- and beta-glucosidases. Besides GG, salt adapted cultures of the aquatic isolates accumulated the dipeptide N-acetylglutaminylglutamine amide (NAGGN) and glutamate. The accumulation of noncharged compatible solutes was also tested in previously identified pseudomonads isolated from the rhizosphere of oilseed rape and potato. The majority of these strains were fluorescent species of the genus Pseudomonas and accumulated trehalose and NAGGN when grown under salt stress conditions. However, rhizosphere isolates of Stenotrophomonas maltophilia synthesized GG and trehalose or only trehalose in a strain-dependent manner. These data indicate that the ability to synthesize GG is widely distributed among slightly or moderately halotolerant pseudomonads.
相容性溶质葡糖基甘油（GG）在蓝细菌中广泛存在，但迄今为止，仅在两种异养细菌中被报道过。通过高效液相色谱法（HPLC）对从波罗的海沿岸地区分离出的约120株细菌进行了筛选，以检测它们合成GG的能力。通过全细胞蛋白的十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS - PAGE）对阳性分离株（26株）进行分组，并通过对每组代表性菌株的16S rRNA基因进行测序和表型特征分析来进行研究。结果表明，所有合成GG的分离株均属于假单胞菌属（狭义），并被分为4个不同的组，尽管没有一个合成GG的分离株能够明确地归入已描述的物种。通过13C核磁共振分析以及用α-和β-葡萄糖苷酶进行酶切消化验证了GG的身份。除了GG之外，水生分离株的盐适应培养物还积累了二肽N - 乙酰谷氨酰胺基谷氨酰胺酰胺（NAGGN）和谷氨酸。还对先前从油菜和马铃薯根际分离出的已鉴定假单胞菌进行了不带电荷的相容性溶质积累情况的测试。这些菌株中的大多数是假单胞菌属的荧光种，在盐胁迫条件下生长时积累海藻糖和NAGGN。然而，嗜麦芽窄食单胞菌的根际分离株以菌株依赖的方式合成GG和海藻糖或仅合成海藻糖。这些数据表明，合成GG的能力在轻度或中度耐盐假单胞菌中广泛分布。
