Microbial communities of the stratified soda Lake Doroninskoe (Transbaikal region)
Microbial communities of the stratified soda Lake Doroninskoe (Transbaikal region)
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DOI：
10.1134/s0026261710030161
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发表时间：
2010-06-01
期刊：
影响因子：
1.5
通讯作者：
Namsaraev, B. B.
中科院分区：
文献类型：
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作者：
Gorlenko, V. M.;Buryukhaev, S. P.;Namsaraev, B. B.
2007年9月，对分层苏打湖Doroninskoe的水体、海岸线微生物垫和小海岸线泥火山中微生物的理化性质、物种组成和垂直分布进行了研究。该湖位于外贝加尔湖地区，在永久冻土区（51 A度25 'N; 112 A度28' E）。现代湖泊的最大深度约为6 m，水的pH值为9.72，近底层的水矿化度为32.3g l（-1）。在夏季，表面含氧层的水柱变得软化到26.5克升（-1），在3.5-4.0米的深度，突然过渡到有氧区含有硫化氢（高达12.56克升（-1））。在上层水层也检测到微量的硫氢化物。水柱的密度分层通常确保稳定的厌氧条件，直到冻结期（11月和12月）。产氧光养生物的初级生产力达到176-230 μ g l（-1）。高速率的暗CO2同化（61-240 μ g l（-1））中检测到的化跃层。在该区域内，检测到硫碱弧菌属硫氧化细菌的嗜碱种（10（4）个细胞ml（-1））。石异养菌盐单胞菌属，以及能够进行硫代硫酸盐氧化的含细菌叶绿素a的需氧无氧光养细菌（AAP）Roseinatrontum sp.。9月份的水透明度极低，因此，在硫化氢层的边界处没有检测到可见的缺氧光合细菌（APBs）集群。然而，根据16 S rRNA基因分析的结果，属于物种Thioalkalicoccus limnaeus、Ectothiorhodospira variabilis、“Ect.大，”和Ect. shaanovii，分离自深淤泥沉积物样品。等方面variabilis和Ect. shaanovii是海岸带藻菌垫中的主要APB种类。耐盐细菌Ect.从泥火山样品中分离出了红细菌属（Rhodobacter）的紫色非硫细菌Shaanovii和玫瑰球菌属（Roseococcus sp.）的AAP。所有这些物种都是嗜碱、中度嗜盐或耐盐微生物。
The physicochemical properties, species composition, and vertical distribution of microorganisms in the water column, shoreline microbial mat, and small shoreline mud volcanoes of the stratified soda Lake Doroninskoe were investigated in September 2007. The lake is located in the Transbaikal region, in the permafrost zone (51A degrees 25'N; 112A degrees 28'E). The maximal depth of the contemporary lake is about 6 m, the pH value of the water is 9.72, and the water mineralization in the near-bottom horizon is 32.3 g l(-1). In summer, the surface oxygen-containing horizon of the water column becomes demineralized to 26.5 g l(-1); at a depth of 3.5-4.0 m, an abrupt transition occurs to the aerobic zone containing hydrosulfide (up to 12.56 g l(-1)). Hydrosulfide was also detected in trace quantities in the upper water horizons. The density stratification of the water column usually ensures stable anaerobic conditions until the freezing period (November and December). The primary production of oxygenic phototrophs reached 176-230 mu g l(-1). High rates of dark CO2 assimilation (61-240 mu g l(-1)) were detected in the chemocline. Within this zone, an alkaliphilic species of sulfur-oxidizing bacteria of the genus Thioalkalivibrio was detected (10(4) cells ml(-1)). Lithoheterotrophic bacteria Halomonas spp., as well as bacteriochlorophyll a-containing aerobic anoxygenic phototrophic bacteria (AAP) Roseinatronobacter sp. capable of thiosulfate oxidation, were isolated from samples collected from the aerobic zone (0-3 m). The water transparency in September was extremely low; therefore, no visible clusters of anoxygenic phototrophic bacteria (APBs) were detected at the boundary of the hydrosulfide layer. However, purple sulfur bacteria which, according to the results of the 16S rRNA gene analysis, belong to the species Thioalkalicoccus limnaeus, Ectothiorhodospira variabilis, "Ect. magna," and Ect. shaposhnikovii, were isolated from samples of deep silt sediments. Ect. variabilis and Ect. shaposhnikovii were the major APB species in the shoreline algo-bacterial mat. The halotolerant bacterium Ect. shaposhnikovii, purple nonsulfur bacteria of the genus Rhodobacter, and AAP of Roseococcus sp. were isolated from the samples collected from mud volcanoes. All these species are alkaliphiles, moderate halophiles, or halotolerant microorganisms.