Cryobiology Laboratory, National Centre for Antarctic and Ocean Research, Vasco-da-Gama, Goa, India.
J Basic Microbiol. 2017 Oct;57(10):827-838. doi: 10.1002/jobm.201700216. Epub 2017 Jul 28.
High throughput V3-16S rRNA amplicon sequencing data was used for evaluating differences between free-living (FL, <1.2-0.2 μm) and particle-associated (PA, >1.2 μm) bacterial communities, and their spatial variation between inner fjord (IF) and outer fjord (OF) of Kongsfjorden. A total of 4,454,142 high quality sequences obtained clustered into 32,058 OTUs. A majority of these sequences were affiliated with Proteobacteria (59.8%), followed by Bacteroidetes (29.02%), Firmicutes (5.9%), Actinobacteria (2.84%), Cyanobacteria (1.04%), and others (1.4%). The highest bacterial diversity was recorded in the inner fjord free-living (IF_FL) fraction whilst the lowest was observed in the outer fjord free-living (OF_FL) fraction. There was a clear spatial variation among FL bacterial communities, while PA communities remained similar at both sampling locations. The free-living bacterial community differs from particle-associated community and had relatively higher abundance (>4-fold) of Alteromonas and Pseudoalteromonas, while PA community was relatively more enriched with Balneatrix, Ulvibacter, Formosa, Candidatus Planktomarina, Sulfitobacter, Loktanella, members of SAR116, and Acidimicrobiales. In addition, two major bacterial taxa, Polaribacter and SAR11, co-occurred in both FL and PA fractions with varied proportions in IF and OF. These results suggest co-occurrence of PA specialist as well as generalist bacterial groups in Kongsfjorden. Further, high bacterial diversity in the IF_FL fraction indicates possible role of glacial inputs in modulating diversity of free-living bacterial community in Kongsfjorden.
高通量 V3-16S rRNA 扩增子测序数据用于评估游离（FL，<1.2-0.2μm）和颗粒相关（PA，>1.2μm）细菌群落之间的差异，以及它们在 Kongsfjorden 内峡湾（IF）和外峡湾（OF）之间的空间变化。总共获得了 4454142 条高质量的序列，聚类为 32058 个 OTUs。这些序列大多数与变形菌门（59.8%）有关，其次是拟杆菌门（29.02%）、厚壁菌门（5.9%）、放线菌门（2.84%）、蓝细菌门（1.04%）和其他门（1.4%）。内峡湾游离（IF_FL）部分的细菌多样性最高，而外峡湾游离（OF_FL）部分的细菌多样性最低。FL 细菌群落之间存在明显的空间差异，而 PA 群落在两个采样地点保持相似。游离细菌群落与颗粒相关群落不同，其 Alteromonas 和 Pseudoalteromonas 的丰度相对较高（>4 倍），而 PA 群落相对更丰富的是 Balneatrix、Ulvibacter、Formosa、Candidatus Planktomarina、Sulfitobacter、Loktanella、SAR116 成员和 Acidimicrobiales。此外，两个主要的细菌类群，Polaribacter 和 SAR11，在内峡湾和外峡湾的游离（FL）和颗粒相关（PA）部分都有共同存在，其在 IF 和 OF 中的比例不同。这些结果表明，在 Kongsfjorden 中，同时存在 PA 专家和一般细菌群体的共同存在。此外，IF_FL 部分的高细菌多样性表明，冰川输入可能在调节 Kongsfjorden 游离细菌群落的多样性方面发挥作用。
