Li Baolian, Zhang Si, Long Lijuan, Huang Sijun
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Science, 164 Xingangxi St., Guangzhou, China.
Graduate University of CAS, Beijing, China.
Curr Microbiol. 2016 Sep;73(3):409-418. doi: 10.1007/s00284-016-1071-3. Epub 2016 Jun 7.
Three bacteriophages (RD-1410W1-01, RD-1410Ws-07, and DS-1410Ws-06) were isolated from the surface water of Sanya Bay, northern South China Sea, on two marine bacteria type strains of the Roseobacter lineage. These phages have an isometric head and a short tail, morphologically belonging to the Podoviridae family. Two of these phages can infect four of seven marine roseobacter strains tested and the other one can infect three of them, showing relatively broader host ranges compared to known N4-like roseophages. One-step growth curves showed that these phages have similar short latent periods (1-2 h) but highly variable burst sizes (27-341 pfu cell(-1)). Their complete genomes show high level of similarities to known N4-like roseophages in terms of genome size, G + C content, gene content, and arrangement. The morphological and genomic features of these phages indicate that they belong to the N4likevirus genus. Moreover, comparative genomic analysis based on 43 N4-like phages (10 roseobacter phages and 33 phages infecting other lineages of bacteria) revealed a core genome of 18 genes shared by all the 43 phages and 38 genes shared by all the ten roseophages. The 38 core genes of N4-like roseophages nearly make up 70 % of each genome in length. Phylogenetic analysis based on the concatenated core gene products showed that our phage isolates represent two new phyletic branches, suggesting the broad genetic diversity of marine N4-like roseophages remains.
从中国南海北部三亚湾的地表水分离出三种噬菌体（RD - 1410W1 - 01、RD - 1410Ws - 07和DS - 1410Ws - 06），它们作用于玫瑰杆菌谱系的两种海洋细菌模式菌株。这些噬菌体具有等轴状头部和短尾部，形态上属于短尾噬菌体科。其中两种噬菌体可感染所测试的七种海洋玫瑰杆菌菌株中的四种，另一种可感染其中三种，与已知的N4样玫瑰噬菌体相比，显示出相对更广泛的宿主范围。一步生长曲线表明，这些噬菌体具有相似的短潜伏期（1 - 2小时），但爆发量高度可变（27 - 341噬菌斑形成单位/细胞）。它们的完整基因组在基因组大小、G + C含量、基因含量和排列方面与已知的N4样玫瑰噬菌体显示出高度相似性。这些噬菌体的形态和基因组特征表明它们属于N4样病毒属。此外，基于43种N4样噬菌体（10种玫瑰杆菌噬菌体和33种感染其他细菌谱系的噬菌体）的比较基因组分析揭示了所有43种噬菌体共有的18个基因的核心基因组以及所有十种玫瑰噬菌体共有的38个基因。N4样玫瑰噬菌体的38个核心基因几乎占每个基因组长度的70%。基于串联核心基因产物的系统发育分析表明，我们分离的噬菌体代表两个新的进化分支，这表明海洋N4样玫瑰噬菌体的广泛遗传多样性仍然存在。
