Das Kangabam Rajiv, Silla Yumnam, Goswami Gunajit, Barooah Madhumita
1Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat-785013, India; 2Advanced Computational and Data Sciences Division, CSIR- North East Institute of Science and Technology, Jorhat-785006, India; 3DBT North East Centre for Agricultural Biotechnology, Assam Agricultural University, Jorhat-785013, India.
Curr Genomics. 2020 Nov;21(7):512-524. doi: 10.2174/1389202921999200716104355.
Microorganisms are an important component of an aquatic ecosystem and play a critical role in the biogeochemical cycle which influences the circulation of the materials and maintains the balance in aquatic ecosystems.
The seasonal variation along with the impact of anthropogenic activities, water quality, bacterial community composition and dynamics in the Loktak Lake, the largest freshwater lake of North East India, located in the Indo-Burma hotspot region was assessed during post-monsoon and winter season through metagenome analysis.
Five soil samples were collected during Post-monsoon and winter season from the Loktak Lake that had undergone different anthropogenic impacts. The metagenomic DNA of the soil samples was extracted using commercial metagenomic DNA extraction kits following the manufacturer's instruction. The extracted DNA was used to prepare the NGS library and sequenced in the Illumina MiSeq platform.
Metagenomics analysis reveals Proteobacteria as the predominant community followed by Acidobacteria and Actinobacteria. The presence of these groups of bacteria indicates nitrogen fixation, oxidation of iron, sulfur, methane, and source of novel antibiotic candidates. The bacterial members belonging to different groups were involved in various biogeochemical processes, including fixation of carbon and nitrogen, producing streptomycin, gramicidin and perform oxidation of sulfur, sulfide, ammonia, and methane.
The outcome of this study provides a valuable dataset representing a seasonal profile across various land use and analysis, targeting at establishing an understanding of how the microbial communities vary across the land use and the role of keystone taxa. The findings may contribute to searches for microbial bio-indicators as biodiversity markers for improving the aquatic ecosystem of the Loktak Lake.
微生物是水生生态系统的重要组成部分，在生物地球化学循环中起着关键作用，影响物质循环并维持水生生态系统的平衡。
通过宏基因组分析，评估位于印度 - 缅甸热点地区的印度东北部最大淡水湖——洛克塔克湖在季风后和冬季的季节变化，以及人为活动、水质、细菌群落组成和动态的影响。
在季风后和冬季，从受到不同人为影响的洛克塔克湖采集了五个土壤样本。使用商业宏基因组DNA提取试剂盒按照制造商的说明提取土壤样本的宏基因组DNA。提取的DNA用于制备NGS文库，并在Illumina MiSeq平台上进行测序。
宏基因组分析表明，变形菌门是主要群落，其次是酸杆菌门和放线菌门。这些细菌类群的存在表明存在固氮、铁、硫、甲烷氧化以及新型抗生素候选物的来源。属于不同类群的细菌成员参与了各种生物地球化学过程，包括碳和氮的固定、产生链霉素、短杆菌肽以及进行硫、硫化物、氨和甲烷的氧化。
本研究的结果提供了一个有价值的数据集，代表了不同土地利用和分析的季节性概况，旨在了解微生物群落在不同土地利用中的变化以及关键类群的作用。这些发现可能有助于寻找微生物生物指标作为生物多样性标记，以改善洛克塔克湖的水生生态系统。
