Bacterial Community Composition Markedly Altered by Coastal Hypoxia
Bacterial Community Composition Markedly Altered by Coastal Hypoxia
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DOI：
10.1007/s12088-019-00790-5
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发表时间：
2019-06-01
影响因子：
3
通讯作者：
Ramaiah, N.
中科院分区：
文献类型：
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作者：
Gomes, Jasmine;Khandeparker, Rakhee;Ramaiah, N.
印度南部和中部西海岸的季风上升流导致了强烈的生物生产力。由于6月至10月上升流后有机物产生过多，且上升流水中溶解氧较低，导致近岸水域发生反硝化作用。隐含地，这些过程应该会带来微生物群落的改变。因此，通过对 16S rRNA 基因克隆进行测序，分析了热带地区经历强烈季节性低氧的地下层细菌的多样性和群落结构。与春季季风期（SIM，3 月）或夏季季风期（SuM，6 月）相比，秋季季风期（FIM，10 月）的缺氧期总体多样性更高。多达 14 个细菌谱系：Gammaproteobacteria (37%)、Alphaproteobacteria (21%)、Cyanobacteria (20%)、Deltaproteobacteria (3%)、Firmicutes (3%)、Betaproteobacteria (2%)、Acidobacteria (2%)、Actinobacteria (7%)、Marinimicrobia (2%)、Bacteroidetes (1%)、在我们的沿海地区发现了疣微菌 (1%)、浮霉菌 (0.4%)、绿屈菌 (0.2%) 和全营养菌 (0.2%)。值得注意的是，浮霉菌、绿屈菌和全营养菌的序列仅在 FIM 期间发现。 SuM 期间 Betaproteobacteria 的序列普遍较高，SIM 期间放线菌和厚壁菌门的序列普遍较高。因此，这项研究有助于认识到受季风影响的热带沿海生态系统中微生物群落可能会经历强烈的时间变化。
Monsoonal upwelling along south and central west coast of India leads to intense biological productivity. As a consequence of excess organic matter production following upwelling during June-October and low dissolved oxygen in the upwelled waters, denitrification occurs in the near shore waters. Implicitly, these processes ought to bring alterations in microbial communities. Therefore, diversity and community structure of bacteria from subsurface layers of a tropical region experiencing intense seasonal lows of oxygen were analyzed through sequencing of 16S rRNA gene clones. The overall diversity was more during hypoxic period of Fall intermonsoon (FIM, October) compared either to Spring intermonsoon (SIM, March) or summer monsoon (SuM, June) months. As many as 14 lineages of bacterial domains: Gammaproteobacteria (37%), Alphaproteobacteria (21%), Cyanobacteria (20%), Deltaproteobacteria (3%), Firmicutes (3%), Betaproteobacteria (2%), Acidobacteria (2%), Actinobacteria (7%), Marinimicrobia (2%), Bacteroidetes (1%), Verrucomicrobia (1%), Planctomycetes (0.4%), Chloroflexi (0.2%) and Omnitrophica bacterium (0.2%), were recognized from our coastal location. Notably, sequences of Planctomycetes, Chloroflexi and Omnitrophica bacterium were found exclusively during FIM. A generally higher representation of sequences of Betaproteobacteria during SuM and of Actinobacteria and Firmicutes during SIM was discernible. This study is thus useful to recognize that microbial community might undergo strong temporal shifts in the monsoon affected tropical coastal ecosystems.