Kohn Timo, Heuer Anja, Jogler Mareike, Vollmers John, Boedeker Christian, Bunk Boyke, Rast Patrick, Borchert Daniela, Glöckner Ines, Freese Heike M, Klenk Hans-Peter, Overmann Jörg, Kaster Anne-Kristin, Rohde Manfred, Wiegand Sandra, Jogler Christian
Leibniz Institut Deutsche Sammlung Von Mikroorganismen und Zellkulturen Braunschweig, Germany.
School of Biology, Newcastle University Newcastle, UK.
Front Microbiol. 2016 Dec 22;7:2079. doi: 10.3389/fmicb.2016.02079. eCollection 2016.
Members of the phylum Planctomycetes are ubiquitous bacteria that dwell in aquatic and terrestrial habitats. While planctomycetal species are important players in the global carbon and nitrogen cycle, this phylum is still undersampled and only few genome sequences are available. Here we describe strain NH11, a novel planctomycete obtained from a crustacean shell (Wadden Sea, Germany). The phylogenetically closest related cultivated species is , sharing only 87% 16S rRNA sequence identity. Previous isolation attempts have mostly yielded members of the genus from water of the German North Sea. On the other hand, only one axenic culture of the genus was obtained from a crustacean thus far. However, the 16S rRNA gene sequence of strain NH11 shares only 80% sequence identity with the closest relative of both genera, and . Thus, strain NH11 is unique in terms of origin and phylogeny. While the pear to ovoid shaped cells of strain NH11 are typical planctomycetal, light-, and electron microscopic observations point toward an unusual variation of cell division through budding: during the division process daughter- and mother cells are connected by an unseen thin tubular-like structure. Furthermore, the periplasmic space of strain NH11 was unusually enlarged and differed from previously known planctomycetes. The complete genome of strain NH11, with almost 9 Mb in size, is among the largest planctomycetal genomes sequenced thus far, but harbors only 6645 protein-coding genes. The acquisition of genomic components by horizontal gene transfer is indicated by the presence of numerous putative genomic islands. Strikingly, 45 "giant genes" were found within the genome of NH11. Subsequent analysis of all available planctomycetal genomes revealed that Planctomycetes as such are especially rich in "giant genes". Furthermore, Multilocus Sequence Analysis (MLSA) tree reconstruction support the phylogenetic distance of strain NH11 from other cultivated Planctomycetes of the same phylogenetic cluster. Thus, based on our findings, we propose to classify strain NH11 as gen. nov., sp. nov., with the type strain NH11, within the phylum Planctomycetes.
浮霉菌门的成员是普遍存在的细菌，栖息于水生和陆地生境中。虽然浮霉菌类物种在全球碳和氮循环中起着重要作用，但该门的采样仍然不足，仅有少数基因组序列可供使用。在此，我们描述了菌株NH11，这是一种从甲壳类动物外壳（德国瓦登海）中获得的新型浮霉菌。系统发育上最接近的相关培养物种是 ，其16S rRNA序列同一性仅为87%。以前的分离尝试大多从德国北海的水中获得 属的成员。另一方面，迄今为止仅从一种甲壳类动物中获得了 属的一种无菌培养物。然而，菌株NH11的16S rRNA基因序列与这两个属的最接近亲属 属和 属的序列同一性仅为80%。因此，菌株NH11在起源和系统发育方面是独特的。虽然菌株NH11梨形至卵形的细胞是典型的浮霉菌细胞，但光学和电子显微镜观察表明其细胞分裂通过出芽存在异常变化：在分裂过程中，子细胞和母细胞通过一个看不见的细管状结构相连。此外，菌株NH11的周质空间异常扩大，与先前已知的浮霉菌不同。菌株NH11的完整基因组大小近9 Mb，是迄今为止测序的最大的浮霉菌基因组之一，但仅含有6645个蛋白质编码基因。众多假定基因组岛的存在表明通过水平基因转移获得了基因组成分。令人惊讶的是，在NH11的基因组中发现了45个“巨型基因”。随后对所有可用的浮霉菌基因组进行分析发现，浮霉菌门本身尤其富含“巨型基因”。此外，多位点序列分析（MLSA）树重建支持了菌株NH11与同一系统发育簇中其他培养浮霉菌的系统发育距离。因此，基于我们的发现，我们建议将菌株NH11分类为浮霉菌门内的 属新属、新种，模式菌株为NH11。
