Mackey Katherine R M, Hunter-Cevera Kristen, Britten Gregory L, Murphy Leslie G, Sogin Mitchell L, Huber Julie A
Earth System Science, University of California IrvineIrvine, CA, United States.
Marine Biological Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and EvolutionWoods Hole, MA, United States.
Front Microbiol. 2017 Aug 9;8:1496. doi: 10.3389/fmicb.2017.01496. eCollection 2017.
are ubiquitous and cosmopolitan cyanobacteria that play important roles in global productivity and biogeochemical cycles. This study investigated the fine scale microdiversity, seasonal patterns, and spatial distributions of in estuarine waters of Little Sippewissett salt marsh (LSM) on Cape Cod, MA. The proportion of reads was higher in the summer than winter, and higher in coastal waters than within the estuary. Variations in the V4-V6 region of the bacterial 16S rRNA gene revealed 12 unique oligotypes. Two distinct communities emerged in early and late summer, each comprising a different set of statistically co-occurring oligotypes from different clades. The early summer community included clades I and IV, which correlated with lower temperature and higher dissolved oxygen levels. The late summer community included clades CB5, I, IV, and VI, which correlated with higher temperatures and higher salinity levels. Four rare oligotypes occurred in the late summer community, and their relative abundances more strongly correlated with high salinity than did other co-occurring oligotypes. The analysis revealed that multiple, closely related oligotypes comprised certain abundant clades (e.g., clade 1 in the early summer and clade CB5 in the late summer), but the correlations between these oligotypes varied from pair to pair, suggesting they had slightly different niches despite being closely related at the clade level. Lack of tidal water exchange between sampling stations gave rise to a unique oligotype not abundant at other locations in the estuary, suggesting physical isolation plays a role in generating additional microdiversity within the community. Together, these results contribute to our understanding of the environmental and ecological factors that influence patterns of microbial community composition over space and time in salt marsh estuarine waters.
是无处不在且分布广泛的蓝细菌，在全球生产力和生物地球化学循环中发挥着重要作用。本研究调查了马萨诸塞州科德角小锡佩维西特盐沼（LSM）河口水中的微小尺度微观多样性、季节模式和空间分布。夏季的 reads 比例高于冬季，沿海水域的比例高于河口内部。细菌 16S rRNA 基因 V4 - V6 区域的变异揭示了 12 种独特的 寡型。在夏初和夏末出现了两个不同的群落，每个群落都由来自不同进化枝的一组不同的统计上共现的 寡型组成。夏初群落包括进化枝 I 和 IV，它们与较低温度和较高溶解氧水平相关。夏末群落包括进化枝 CB5、I、IV 和 VI，它们与较高温度和较高盐度水平相关。四种罕见的寡型出现在夏末群落中，它们的相对丰度与高盐度的相关性比其他共现寡型更强。分析表明，多个密切相关的寡型组成了某些丰富的进化枝（例如夏初的进化枝 1 和夏末的进化枝 CB5），但这些寡型之间的相关性因对而异，表明它们尽管在进化枝水平上密切相关，但生态位略有不同。采样站之间缺乏潮水交换导致了一种在河口其他位置不丰富的独特寡型，表明物理隔离在群落内产生额外的微观多样性方面发挥了作用。总之，这些结果有助于我们理解影响盐沼河口水中 微生物群落组成在空间和时间上的模式的环境和生态因素。
