Tanaka Daisuke, Takahashi Toyo, Yamashiro Yoko, Tanaka Hitoshi, Kimochi Yuzuru, Nishio Masaki, Sakatoku Akihiro, Nakamura Shogo
Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama, 930-8555, Japan.
Center for Environmental Science in Saitama (CESS), 914 Kamitanadare, Kazo, Saitama, 347-0115, Japan.
World J Microbiol Biotechnol. 2017 Nov 13;33(12):212. doi: 10.1007/s11274-017-2377-4.
The aim of this study was to improve our understanding of seasonal variations and the effects of physicochemical conditions on the bacterioplankton communities in two small rivers, the Moo and Nakayachi Rivers in the Himi region of central Japan. These rivers are inhabited by unionid freshwater mussels, which are used for oviposition by the endangered Itasenpara bitterling (Acheilognathus longipinnis). Water samples were collected every month between March 2011 and February 2012. Changes in bacterioplankton community structures were analysed using an approach that did not require cultivating the bacteria and involved PCR and denaturing gradient gel electrophoresis. The bacterioplankton community structures in the two rivers were similar in all seasons except winter. The bacterial sequences identified were dominated by typical freshwater Actinobacteria, Bacteroidetes, Cyanobacteria, α-Proteobacteria, and β-Proteobacteria bacterioplankton. Many β-Proteobacteria species were detected in all seasons, but Bacteroidetes species were dominant in the winter. The bacterioplankton community structures were affected by biochemical oxygen demand, chemical oxygen demand, chlorophyll-a concentration, water depth, and water temperature. These results provide a foundation for a more detailed understanding of the conditions that provide a suitable unionid habitat.
本研究的目的是增进我们对日本中部冰见地区的小牧川和中八知川这两条小河中浮游细菌群落的季节变化以及理化条件影响的理解。这些河流中有河蚌，濒危物种伊达森原田苦恶鱼（Acheilognathus longipinnis）会在河蚌体内产卵。2011年3月至2012年2月期间每月采集水样。采用一种无需培养细菌的方法，通过聚合酶链反应（PCR）和变性梯度凝胶电泳分析浮游细菌群落结构的变化。除冬季外，两条河流中浮游细菌的群落结构在所有季节都相似。鉴定出的细菌序列主要由典型的淡水放线菌、拟杆菌、蓝细菌、α-变形菌和β-变形菌浮游细菌组成。所有季节均检测到许多β-变形菌物种，但拟杆菌物种在冬季占主导地位。浮游细菌群落结构受生化需氧量、化学需氧量、叶绿素a浓度、水深和水温的影响。这些结果为更详细地了解提供适宜河蚌栖息地的条件奠定了基础。
