The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, 060-0819, Japan.
Microb Ecol. 2012 Apr;63(3):496-508. doi: 10.1007/s00248-011-9983-8. Epub 2011 Nov 23.
Relationships between environmental factors and bacterial communities were investigated in 41 freshwater lakes located in mountainous regions of eastern Japan. Bacterioplankton community composition (BCC) was determined by polymerase chain reaction-denaturing gradient gel electrophoresis of the 16S rRNA gene and then evaluated on the basis of physicochemical and biological variables of the lakes. Canonical correspondence analysis revealed that BCC of oligotrophic lakes was significantly influenced by dissolved organic carbon (DOC) content, but its effect was not apparent in the analysis covering all lakes including mesotrophic and eutrophic ones. The generalized linear model showed the negative association of DOC on the taxon richness of bacterioplankton communities. DOC was positively correlated with the catchment area per lake volume, suggesting that a large fraction of DOC supplied to the lake was derived from terrestrial sources. These results suggest that allochthonous DOC has a significant effect on bacterioplankton communities especially in oligotrophic lakes. The genus Polynucleobacter was detected most frequently. The occurrence of Polynucleobacter species was positively associated with DOC and negatively associated with total phosphorus (TP) levels. In addition, TP had a stronger effect than DOC, suggesting that oligotrophy is the most important factor on the occurrence of this genus.
本研究调查了日本东部山区 41 个淡水湖泊中环境因子与细菌群落之间的关系。采用聚合酶链反应-变性梯度凝胶电泳（PCR-DGGE）对 16S rRNA 基因进行分析，从而确定浮游细菌群落组成（BCC），并根据湖泊的理化和生物学变量对其进行评估。典范对应分析表明，贫营养湖泊的 BCC 受溶解有机碳（DOC）含量的显著影响，但在涵盖所有湖泊（包括中营养和富营养湖泊）的分析中，这种影响并不明显。广义线性模型表明，DOC 与浮游细菌群落的分类丰富度呈负相关。DOC 与流域面积与湖泊体积之比呈正相关，表明有很大一部分输入湖泊的 DOC 来自陆地源。这些结果表明，异源 DOC 对细菌群落，特别是贫营养湖泊中的细菌群落具有显著影响。聚球藻属（Polynucleobacter）的出现频率最高。 Polynucleobacter 属的出现与 DOC 呈正相关，与总磷（TP）水平呈负相关。此外，TP 的影响比 DOC 更强，这表明贫营养是该属出现的最重要因素。
