Structural diversity of diether lipids in carbonate chimneys at the Lost City Hydrothermal Field
Structural diversity of diether lipids in carbonate chimneys at the Lost City Hydrothermal Field
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DOI：
10.1016/j.orggeochem.2009.09.004
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发表时间：
2009-12-01
影响因子：
3
通讯作者：
Summons, Roger E.
中科院分区：
文献类型：
--
作者：
Bradley, Alexander S.;Fredricks, Helen;Summons, Roger E.
失落之城热液田拥有独特的微生物生态系统，该生态系统由蛇纹石化反应的产物支持。这里的碳酸钙烟囱含有丰富的异戊二烯和非异戊二烯醚脂质，其结构多样性与冷泉碳酸盐结壳中发现的相似，其中甲烷厌氧氧化（AOM）是主要的生物地球化学过程。失落之城的微生物群落包括丰富的古细菌，它们很大程度上属于产甲烷菌目中的单一系统型。源自这些古细菌的类异戊二烯二醚具有包含磷脂酰甘油或单糖基部分的极性头基，尽管在这些碳酸盐中检测到的许多类异戊二烯二醚缺乏头基。失落之城的非类异戊二烯二醚脂质主要是糖脂。此前尚未从任何环境或细菌分离物中报道过糖基非异戊二烯二醚。糖脂在古细菌中很常见，其中含有与甘油连接的异戊二烯烃核心醚。糖脂也存在于一些细菌中，并且在这些非异戊二烯脂肪酸链中与甘油酯连接。然而，失落之城的糖基化非异戊二烯二醚脂质含有以前未检测到的古菌和细菌特征的组合，这可能是对喷口环境的适应性反应。我们假设，利用糖基头基代替磷脂酰头基是在必需营养素含量低的液体中生长的生物体保存磷酸盐的一种策略。 (C) 2009 Elsevier Ltd. 保留所有权利。
The Lost City Hydrothermal Field hosts a distinctive microbial ecosystem that is supported by the products of serpentinization reactions. The calcium carbonate chimneys here contain abundant isoprenoidal and non-isoprenoidal ether lipids, the structural diversity of which is similar to that found in carbonate crusts at cold seeps where anaerobic oxidation of methane (AOM) is the dominant biogeochemical process. The microbial community at Lost City includes abundant archaea, which largely belong to a single phylotype within the methanogenic Methanosarcinales. Isoprenoidal diethers derived from these archaea have polar head groups comprising phosphatidylglycerol or monoglycosyl moieties, although many isoprenoidal diethers detected in these carbonates lack head groups.The non-isoprenoidal diether lipids at Lost City are largely glycolipids. Glycosydic non-isoprenoidal diethers have not previously been reported from any environments or bacterial isolates. Glycolipids are common in archaea where they contain isoprenoidal hydrocarbon cores ether linked to glycerol. Glycolipids also occur in some bacteria and in these non-isoprenoidal fatty acid chains are ester linked to glycerol. However, the glycosylated non-isoprenoidal diether lipids at Lost City contain a previously undetected combination of archaeal and bacterial traits that might be an adaptive response to the vent environment. We hypothesize that utilization of glycosyl head groups instead of phosphatidyl head groups is a strategy for conservation of phosphate by organisms growing in fluids low in this essential nutrient. (C) 2009 Elsevier Ltd. All rights reserved.