In late 2011, Thailand experienced one of the most damaging floods of the century. Flooding spread through the provinces of Northern, Northeastern and Central Thailand along the Mekong and Chao Phraya river basins and lasted for months in some areas, especially in the Central Plain. The flood ecosystem is considered a temporally variable ecological-niche within the aquatic environment that can have a major impact on microbial communities related to water quality and public health.
In this study, bacterial and fungal diversity in sediments and waters collected from ten flood areas in Bangkok and its suburbs, covering residential and agricultural areas, were analyzed using high-throughput 454 pyrosequencing of 16S rRNA gene and internal transcribed spacer sequences. Analysis of microbial community showed differences in taxa distribution in water and sediment with variations in the diversity of saprophytic microbes and sulfate/nitrate reducers among sampling locations, suggesting differences in microbial activity in the habitats. Overall, Proteobacteria represented a major bacterial group in waters, while this group co-existed with Firmicutes, Bacteroidetes, and Actinobacteria in sediments. Anaeromyxobacter, Steroidobacter, and Geobacter were the dominant bacterial genera in sediments, while Sulfuricurvum, Thiovirga, and Hydrogenophaga predominated in waters. For fungi in sediments, Ascomycota, Glomeromycota, and Basidiomycota, particularly in genera Philipsia, Rozella, and Acaulospora, were most frequently detected. Chytridiomycota and Ascomycota were the major fungal phyla, Rhizophlyctis and Mortierella were the most frequently detected fungal genera in water. Diversity of sulfate-reducing bacteria, related to odor problems, was further investigated using analysis of the dsrB gene which indicated the presence of sulfate-reducing bacteria of families Desulfobacteraceae, Desulfobulbaceae, Syntrobacteraceae, and Desulfoarculaceae in the flood sediments. The work provides a foundation for more detailed studies on how microbial communities in flood ecosystems affect physicochemical changes in the environment and impact human communities.
This study is a collaborative work of researchers from Chulalongkorn University, North Dakota State University (USA) and BIOTEC.
The full article can be accessed here.
Ref: Mhuantong, W.,Wongwilaiwalin, S.,Laothanachareon, T.,Eurwilaichitr, L.,Tangphatsornruang, S.,Boonchayaanant, B.,Limpiyakorn, T.,Pattaragulwanit, K.,Punmatharith, T., McEvoy, J.,Khan, E.,Rachakornkij, M. andChampreda, V. (2015) Survey of Microbial Diversity in Flood Areas during Thailand 2011 Flood Crisis Using High-Throughput Tagged Amplicon Pyrosequencing. PLOS ONE, 10 (5): e0128043
Posted on 29 September 2015