Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain.
Int Microbiol. 2010 Jun;13(2):67-77. doi: 10.2436/20.1501.01.112.
Seven maritime Antarctic lakes located on Byers Peninsula (Livingston Island, South Shetland Islands) were surveyed to determine the relationship between planktonic bacterial community composition and environmental features. Specifically, the extent to which factors other than low temperature determine the composition of bacterioplankton assemblages of maritime Antarctic lakes was evaluated. Both deep and shallow lakes in the central plateau of the Peninsula, as well as a coastal lake, were studied in order to fully account for the environmental heterogeneity of the Peninsula's lakes. The results showed that shallow coastal lakes display eutrophic conditions, mainly due to the influence of marine animals, whereas plateau lakes are generally deeper and most are oligotrophic, with very limited inputs of nutrients and organic matter. Meso-eutrophic shallow lakes are also present on the Peninsula; they contain microbial mats and a higher trophic status because of the biologically mediated active nutrient release from the sediments. Diversity studies of the lakes' planktonic bacterial communities using molecular techniques showed that bacterial diversity is lower in eutrophic than in oligotrophic lakes. The former also differed in community composition with respect to dominant taxa. Multivariate statistical analyses of environmental data yielded the same clustering of lakes as obtained based on the DGGE band pattern after DNA extraction and amplification of 16S rRNA gene fragments. Thus, even in extremely cold lakes, the bacterial community composition parallels other environmental factors, such as those related to trophic status. This correspondence is not only mediated by the influence of marine fauna but also by processes including sediment and ice melting dynamics. The bacterial community can therefore be considered to be equally representative as environmental abiotic variables in demonstrating the environmental heterogeneity among maritime Antarctic lakes.
对位于拜尔斯半岛（南设得兰群岛，利文斯顿岛）的七个海洋南极湖泊进行了调查，以确定浮游细菌群落组成与环境特征之间的关系。具体而言，评估了除低温以外的其他因素对海洋南极湖泊细菌浮游生物组合组成的影响程度。对半岛中部高原的深湖和浅湖以及一个沿海湖泊进行了研究，以充分说明该半岛湖泊的环境异质性。结果表明，浅沿海湖泊呈现富营养化条件，主要是由于海洋动物的影响，而高原湖泊通常较深，大多数为贫营养型，营养物质和有机物的输入非常有限。半岛上还存在中营养浅湖泊；由于生物介导的从沉积物中释放活性营养物质，它们含有微生物垫和更高的营养状态。使用分子技术对湖泊浮游细菌群落进行的多样性研究表明，富营养化湖泊的细菌多样性低于贫营养化湖泊。前者在群落组成上也与主要类群不同。对环境数据的多元统计分析得出的湖泊聚类结果与基于 DNA 提取和 16S rRNA 基因片段扩增后的 DGGE 条带模式得出的聚类结果相同。因此，即使在极冷的湖泊中，细菌群落组成也与其他环境因素（如与营养状况有关的因素）平行。这种对应不仅是由海洋动物群的影响介导的，还包括包括沉积物和冰融化动力学等过程。因此，细菌群落可以被认为与环境非生物变量一样，能够很好地代表海洋南极湖泊之间的环境异质性。
