Vipindas Puthiya Veettil, Venkatachalam Siddarthan, Jabir Thajudeen, Yang Eun Jin, Cho Kyoung-Ho, Jung Jinyoung, Lee Youngju, Krishnan Kottekkatu Padinchati
Arctic Ecology and Biogeochemistry Division, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, Goa, 403 804, India.
Division of Polar Ocean Sciences, Korea Polar Research Institute, 26 Songdo-dong, Yeonsu-gu, Incheon, 21990, Republic of Korea.
Microb Ecol. 2023 May;85(4):1150-1163. doi: 10.1007/s00248-022-01992-z. Epub 2022 Mar 28.
The environmental variations and their interactions with the biosphere are vital in the Arctic Ocean during the summer sea-ice melting period in the current scenario of climate change. Hence, we analysed the vertical distribution of bacterial and archaeal communities in the western Arctic Ocean from sea surface melt-ponds to deep water up to a 3040 m depth. The distribution of microbial communities showed a clear stratification with significant differences among different water depths, and the water masses in the Arctic Ocean - surface mixed layer, Atlantic water mass and deep Arctic water - appeared as a major factor explaining their distribution in the water column. A total of 34 bacterial phyla were detected in the seawater and 10 bacterial phyla in melt-ponds. Proteobacteria was the dominant phyla in the seawater irrespective of depth, whereas Bacteroidota was the dominant phyla in the melt-ponds. A fast expectation-maximization microbial source tracking analysis revealed that only limited dispersion of the bacterial community was possible across the stratified water column. The surface water mass contributed 21% of the microbial community to the deep chlorophyll maximum (DCM), while the DCM waters contributed only 3% of the microbial communities to the deeper water masses. Atlantic water mass contributed 37% to the microbial community of the deep Arctic water. Oligotrophic heterotrophic bacteria were dominant in the melt-ponds and surface waters, whereas chemoautotrophic and mixotrophic bacterial and archaeal communities were abundant in deeper waters. Chlorophyll and ammonium were the major environmental factors that determined the surface microbial communities, whereas inorganic nutrient concentrations controlled the deep-water communities.
在当前气候变化的情景下，北冰洋夏季海冰融化期的环境变化及其与生物圈的相互作用至关重要。因此，我们分析了北冰洋西部从海面融池到深度达3040米的深层水的细菌和古菌群落的垂直分布。微生物群落的分布呈现出明显的分层，不同水深之间存在显著差异，北冰洋的水体——表层混合层、大西洋水团和深层北极水——似乎是解释它们在水柱中分布的主要因素。在海水中共检测到34个细菌门，在融池中检测到10个细菌门。无论深度如何，变形菌门都是海水中的优势菌门，而拟杆菌门是融池中的优势菌门。快速期望最大化微生物源追踪分析表明，细菌群落仅能在分层水柱中有限扩散。表层水体对深层叶绿素最大值（DCM）的微生物群落贡献了21%，而DCM水体对更深层水体的微生物群落仅贡献了3%。大西洋水团对深层北极水的微生物群落贡献了37%。贫营养异养细菌在融池和表层水体中占主导地位，而化学自养和混合营养的细菌和古菌群落在更深层水体中丰富。叶绿素和铵是决定表层微生物群落的主要环境因素，而无机营养物浓度控制着深层水体群落。
