Hot Lake (Oroville, WA) is an athalassohaline epsomite lake that can have precipitating concentrations of MgSO4salts, mainly epsomite. Little biotic study has been done on epsomite lakes and it was unclear whether microbes isolated from epsomite lakes and their margins would fall within recognized halotolerant genera, common soil genera or novel phyla. Our initial study cultivated and characterized epsotolerant bacteria from the lake and its margins. Approximately 100 aerobic heterotrophic microbial isolates were obtained by repetitive streak-plating in high-salt media including either 10% NaCl or 2 M MgSO4. The collected isolates were all bacteria, nearly evenly divided between Gram-positive and Gram-negative clades, the most abundant genera beingHalomonas, Idiomarina, Marinobacter, Marinococcus, Nesterenkonia, NocardiopsisandPlanococcus. Bacillus, Corynebacterium, Exiguobacterium, KocuriaandStaphylococcusalso were cultured. This initial study included culture-independent community analysis of direct DNA extracts of lake margin soil using PCR-based clone libraries and 16S rRNA gene phylogeny. Clones assigned to Gram-positive bacterial clades (70% of total clones) were dominated by sequences related to uncultured actinobacteria. There were abundantDeltaproteobacteriaclones related to bacterial sulphur metabolisms and clones ofLegionellaandCoxiella. These epsomite lake microbial communities seem to be divided between bacteria primarily associated with hyperhaline environments rich in NaCl and salinotolerant relatives of common soil organisms. Archaea appear to be in low abundance and none were isolated, despite near-saturated salinities. Growth of microbes at very high concentrations of magnesium and other sulphates has relevance to planetary protection and life-detection missions to Mars, where scant liquid water may form as deliquescent brines and appear as eutectic liquids.

中文翻译：

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华盛顿州 Hot Lake 细菌组合的分子和表型特征，高浓度硫酸镁的环境及其与火星的相关性

Hot Lake (Oroville, WA) 是一个深盐泻湖，可沉淀出浓度较高的 MgSO4盐类，主要是泻盐。很少对泻湖进行生物研究，尚不清楚从泻湖及其边缘分离出的微生物是否属于公认的耐盐属、常见土壤属或新门。我们的初步研究从湖泊及其边缘培养和表征了抗逆性细菌。通过在包括 10% NaCl 或 2 M MgSO 的高盐介质中重复划线电镀，获得了大约 100 个好氧异养微生物分离物4. 收集的分离物都是细菌，几乎均匀地分为革兰氏阳性和革兰氏阴性进化枝，最丰富的属是Halomonas, Idiomarina, Marinobacter, Marinococcus, Nesterenkonia, Nocardiopsis和球菌属。芽孢杆菌属、棒状杆菌属、微小杆菌属、Kocuria和葡萄球菌也被培养了。这项初步研究包括使用基于 PCR 的克隆文库和 16S rRNA 基因系统发育对湖缘土壤的直接 DNA 提取物进行与培养无关的群落分析。分配给革兰氏阳性细菌进化枝的克隆（占总克隆的 70%）主要是与未培养的放线菌相关的序列。有丰富的变形杆菌门与细菌硫代谢相关的克隆和军团菌和胼胝体. 这些泻湖微生物群落似乎分为主要与富含 NaCl 的高盐环境相关的细菌和常见土壤生物的耐盐亲属。尽管盐度接近饱和，但古生菌的丰度似乎很低，没有一个被分离出来。在非常高浓度的镁和其他硫酸盐下微生物的生长与行星保护和火星生命探测任务有关，在火星上，液态水可能会形成潮解性盐水并以低共熔液体的形式出现。