Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India.
Department of Biogeochemistry and Geology, Tropical Marine Microbiology, Leibniz Center for Tropical Marine Research, Bremen, Germany.
PLoS One. 2020 Feb 25;15(2):e0221543. doi: 10.1371/journal.pone.0221543. eCollection 2020.
Anthropogenic perturbations have strong impact on water quality and ecological health of mangrove areas of Indian Sundarbans. Diversity in microbial community composition is important causes for maintaining the health of the mangrove ecosystem. However, microbial communities of estuarine water in Indian Sundarbans mangrove areas and environmental determinants that contribute to those communities were seldom studied.
Nevertheless, this study attempted first to report bacterial and archaeal communities simultaneously in the water from Matla River and Thakuran River of Maipith coastal areas more accurately using 16S rRNA gene-based amplicon approaches. Attempt also been made to assess the capability of the environmental parameters for explaining the variation in microbial community composition.
Our investigation indicates the dominancy of halophilic marine bacteria from families Flavobacteriaceae and OM1 clade in the water with lower nutrient load collected from costal regions of a small Island of Sundarban Mangroves (ISM). At higher eutrophic conditions, changes in bacterial communities in Open Marine Water (OMW) were detected, where some of the marine hydrocarbons degrading bacteria under families Oceanospirillaceae and Spongiibacteraceae were dominated. While most abundant bacterial family Rhodobacteracea almost equally (18% of the total community) dominated in both sites. Minor variation in the composition of archaeal community was also observed between OMW and ISM. Redundancy analysis indicates a combination of total nitrogen and dissolved inorganic nutrients for OMW and for ISM, salinity and total nitrogen was responsible for explaining the changes in their respective microbial community composition.
Our study contributes the first conclusive overview on how do multiple environmental/anthropogenic stressors (salinity, pollution, eutrophication, land-use) affect the Sundarban estuary water and consequently the microbial communities in concert. However, systematic approaches with more samples for evaluating the effect of environmental pollutions on mangrove microbial communities are recommended.
人为干扰对印度孙德尔本斯红树林地区的水质和生态健康有强烈影响。微生物群落组成的多样性是维持红树林生态系统健康的重要原因。然而，印度孙德尔本斯红树林地区河口水中的微生物群落及其对这些群落有贡献的环境决定因素很少受到研究。
然而，本研究首次试图使用基于 16S rRNA 基因的扩增子方法更准确地同时报告来自马蒂拉河和塔库兰河的沿海地区马皮思的河口水中的细菌和古菌群落。还试图评估环境参数解释微生物群落组成变化的能力。
我们的调查表明，在来自孙德尔本斯红树林（ISM）小岛屿沿海地区的低营养负荷的水中，优势的海洋嗜盐菌来自黄杆菌科和 OM1 丛。在较高的富营养化条件下，在开放海洋水中（OMW）检测到细菌群落的变化，其中一些海洋烃降解菌在海洋螺旋菌科和海绵杆菌科中占优势。而最丰富的细菌科红杆菌科几乎同样（占总群落的 18%）在两个地点都占主导地位。在 OMW 和 ISM 之间，古菌群落的组成也观察到了较小的变化。冗余分析表明，总氮和溶解无机养分的组合是 OMW 的原因，而 ISM 的原因是盐度和总氮，负责解释它们各自微生物群落组成的变化。
我们的研究首次提供了关于多种环境/人为胁迫（盐度、污染、富营养化、土地利用）如何影响孙德尔本斯河口水，并因此协同影响微生物群落的明确概述。然而，建议采用更多样本的系统方法来评估环境污染对红树林微生物群落的影响。
