Department of Biology and the Center for Sustainability and the Environment, Albion College, 611 East Porter Street, Albion, MI, 49224, USA.
Microb Ecol. 2018 Apr;75(3):598-608. doi: 10.1007/s00248-017-1081-0. Epub 2017 Sep 29.
The Laurentian Great Lakes, including Lakes Superior, Michigan, Huron, Erie, and Ontario, located in the eastern part of North America are considered the largest of freshwater lakes in the world; however, very little is known about the diversity and distribution of indigenous microbial assemblages within these vast bodies of freshwater systems. Therefore, to delineate the microbial structure and community composition in these aquatic environments, combinations of high-throughput sequencing and fluorescent in situ hybridization (FISH) approaches were utilized to quantitatively characterize the occurrence, diversity, and distribution of bacterioplankton assemblages in six different sites located along the coastal regions of Lakes Michigan, Huron, and Erie. Phylogenetic examination showed a diverse bacterial community belonging to 11 different taxonomic groups. Pyrosequencing results revealed that the majority of the sequences were clustered into four main groups, i.e., Proteobacteria, Bacteriodetes, Actinobacteria, and Cyanobacteria, while fluorescent in situ hybridization also showed the numerical dominance of members of the Gammaproteobacteria and the Cytophaga-Flavobacterium in the six lake sites examined. Overall, the assemblages were shown to be quite diverse in distribution among the lake sites examined, comprising mostly of various heterotrophic populations, with the exception of the Lake Erie-Sandusky Bay site with more than 50% domination by autotrophic Cyanobacteria. This indicates that combinations of factors including water chemistry and various anthropogenic disturbances as well as the lake morphometric characteristics are probably influencing the community structure and diversity of the bacterial assemblages within the systems.
北美东部的 Laurentian 大湖包括苏必利尔湖、密歇根湖、休伦湖、伊利湖和安大略湖，被认为是世界上最大的淡水湖；然而，对于这些广阔的淡水系统内部土著微生物组合的多样性和分布情况，人们知之甚少。因此，为了描绘这些水生环境中的微生物结构和群落组成，本研究采用高通量测序和荧光原位杂交（FISH）方法的组合，定量描述了沿密歇根湖、休伦湖和伊利湖沿海地区的六个不同地点的浮游细菌组合的发生、多样性和分布情况。系统发育分析表明，该细菌群落属于 11 个不同的分类群，具有多样性。焦磷酸测序结果表明，大多数序列聚类为四个主要组，即变形菌门、拟杆菌门、放线菌门和蓝细菌门，而荧光原位杂交也表明，在六个湖泊地点中，γ-变形菌门和噬纤维菌-黄杆菌门的成员数量上占据优势。总的来说，在所研究的湖泊地点中，组合的分布具有相当大的多样性，主要由各种异养种群组成，除了伊利湖-桑达斯基湾地点，其 50%以上的优势种群为自养蓝细菌。这表明，包括水化学和各种人为干扰以及湖泊形态特征在内的多种因素可能会影响系统内细菌组合的群落结构和多样性。
