Institute of Ecosystem Study, CNR, Verbania-Pallanza, Italy.
FEMS Microbiol Ecol. 2013 Aug;85(2):293-301. doi: 10.1111/1574-6941.12118. Epub 2013 Apr 15.
We studied the phylogenetic diversity of nonmarine picocyanobacteria broadening the sequence data set with 43 new sequences of the 16S rRNA gene. The sequences were derived from monoclonal strains isolated from four volcanic high-altitude athalassohaline lakes in Mexico, five glacial ultraoligotrophic North Patagonian lakes and six Italian lakes of glacial, volcanic and morenic origin. The new sequences fall into a number of both novel and previously described clades within the phylogenetic tree of 16S rRNA gene. The new cluster of Lake Nahuel Huapi (North Patagonia) forms a sister clade to the subalpine cluster II and the marine Synechococcus subcluster 5.2. Our finding of the novel clade of 'halotolerants' close to the marine subcluster 5.3 (Synechococcus RCC307) constitutes an important demonstration that euryhaline and marine strains affiliate closely. The intriguing results obtained shed new light on the importance of the nonmarine halotolerants in the phylogenesis of picocyanobacteria.
我们研究了非海洋蓝藻的系统发育多样性，通过 16S rRNA 基因的 43 个新序列扩展了序列数据集。这些序列来自于从墨西哥四个火山高海拔盐水湖、五个冰川超寡营养北巴塔哥尼亚湖和六个意大利冰川、火山和冰碛湖分离的单克隆菌株。新序列属于 16S rRNA 基因系统发育树中许多新的和以前描述的分支。纳韦尔瓦皮湖（北巴塔哥尼亚）的新集群与亚高山集群 II 和海洋聚球藻亚群 5.2 形成姐妹群。我们发现的靠近海洋亚群 5.3（聚球藻 RCC307）的“耐盐”新集群，是对广盐性和海洋菌株密切相关的重要证明。这些有趣的结果表明，耐盐非海洋蓝藻在蓝藻的系统发育中具有重要意义。
