Jeju National University, Jeju, Jeju Special Self-Governing Province, 63243, Republic of Korea.
Microbial Ecophysiology Group, Faculty of Biology/Chemistry, University of Bremen, Bremen, Germany.
Microb Ecol. 2021 Apr;81(3):579-591. doi: 10.1007/s00248-020-01616-4. Epub 2020 Oct 16.
To understand bacterial biogeography in response to the hydrographic impact of climate change derived from the Arctic glacier melting, we surveyed bacterial diversity and community composition using bacterial 16S rRNA gene metabarcoding in the seawaters of Kongsfjorden, Svalbard, during summer 2016. In the present study, bacterial biogeography in the Kongsfjorden seawaters showed distinct habitat patterns according to water mass classification and habitat transition between Atlantic and fjord surface waters. Moreover, we estimated phylogenetic diversity of bacterial communities using the net relatedness, nearest taxon, and beta nearest taxon indices. We found the influence of freshwater input from glacier melting in shaping bacterial assemblage composition through the stochastic model. We further evaluated bacterial contributions to phytoplankton-derived dimethylsulfoniopropionate (DMSP) using a quantitative PCR (qPCR) measurement with demethylation (dmdA) and cleavage (dddP) genes of two fundamentally different processes. Our qPCR results imply that bacterial DMSP degradation follows the Atlantic inflow during summer in Kongsfjorden. These findings suggest that the Atlantic inflow and glacial melting influence bacterial community composition and assembly processes and thus affect the degradation of phytoplankton-derived organic matter in an Arctic fjord.
为了了解气候变化引起的北极冰川融化对水文学的影响下细菌的生物地理学分布，我们在 2016 年夏季利用细菌 16S rRNA 基因宏条形码技术对斯瓦尔巴群岛康斯峡湾的海水进行了细菌多样性和群落组成的调查。在本研究中，康斯峡湾海水的细菌生物地理学根据水团分类和大西洋与峡湾表面水之间的栖息地转换呈现出明显的模式。此外，我们使用净亲缘关系、最近分类单元和β最近分类单元指数来估计细菌群落的系统发育多样性。我们发现，冰川融化带来的淡水输入通过随机模型影响了细菌组合的组成。我们进一步通过定量 PCR（qPCR）测量来评估细菌对源自浮游植物的二甲基巯基丙酸（DMSP）的贡献，该测量使用了两个完全不同的过程的去甲基化（dmdA）和裂解（dddP）基因。我们的 qPCR 结果表明，在康斯峡湾，细菌 DMSP 的降解遵循夏季的大西洋流入。这些发现表明，大西洋流入和冰川融化影响细菌群落组成和组装过程，从而影响北极峡湾中源自浮游植物的有机物质的降解。
