Alphaproteobacterial dominance in a large mesotrophic lake (Lake Biwa, Japan)

作者：Nishimura Yoko; Nagata Toshi^*

来源：Aquatic Microbial Ecology, 2007, 48(3): 231-240.

DOI：10.3354/ame048231

• alphaproteobacteria
• bacterial community structure
• filamentous bacteria
• large lake
• Lake Biwa
• fluorescence in situ hybridization

We used fluorescence in situ hybridization to examine seasonal variation over 7 mo in the relative abundance of phylogenetic groups of bacterioplankton in the large (area 673.8 km(2), maximum depth 104 m) mesotrophic, freshwater Lake Biwa, Japan. Alphaproteobacteria dominated the community, with relative abundances (42 +/- 12% [mean +/- SD, n = 40] of total prokaryote abundance) much higher than those in other freshwater communities described in the literature. The second most abundant groups were Actinobacteria (14 +/- 9.6%) and Betaproteobacteria (12 +/- 6%) followed by the Cytophaga-Flavobacteria (CF) cluster (5.8 +/- 3.5%). Filament communities were less diverse, consisting of only Alphaproteobacteria (64 +/- 15% [n = 44] of the total filament abundance) and the CF cluster (28 +/- 16%). Although seasonal patterns were different among different phylogenetic and morphotypic groups, Alphaproteobacteria consistently dominated the community throughout the seasons. Our data suggest that Lake Biwa differs from other lakes in some key aspects, urging further investigation of detailed taxonomic compositions and ecological features of freshwater Alphaproteobacteria.

• 出版日期2007-8-9