1Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, 99, Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
2Bacterial Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea.
Int J Syst Evol Microbiol. 2018 Sep;68(9):2960-2966. doi: 10.1099/ijsem.0.002929. Epub 2018 Jul 20.
Three Gram-negative, non-spore-forming, rod-shaped and motile bacterial strains, designated MMS16-UL250, MMS16-UL253 and MMS16-UL482, were isolated from coastal seawater and subjected to taxonomic characterization. All isolates grew at 4-30 °C (optimum, 25 °C), at pH 6-10 (pH 7) and in the presence of up to 8 % NaCl (2.5-4.5 %). The 16S rRNA gene sequence similarities between the three isolates and Shewanella algicola St-6, the closest species, were 98.1-99.2 %, and those among the isolates were 98.5-99.0 %. In the phylogenetic tree, MMS16-UL250 formed a cluster with S. algicola St-6, but the DNA-DNA relatedness between the two strains was 28.8±1.5 %, thus confirming their separation at species level. The other two strains formed separate phylogenetic lines respectively. The main quinones for all strains were Q-7, Q-8, MK-7 and MMK-7, which is typical for Shewanella. The major polar lipids of all strains were phosphatidylglycerol and phosphatidylethanolamine, and the common major fatty acid was a summed feature consisting of C16 : 1ω7c and/or C16 : 1ω6c while the proportions varied among the three strains. The DNA G+C contents of the strains also varied between 42.1 and 43.7 mol%. Phenotypic properties distinguished each strain from S. algicola as well as from one another. Based on the polyphasic analysis, each strain is considered to represent a novel species of Shewanella, for which the names Shewanellasaliphila sp. nov. (type strain, MMS16-UL250=KCTC 62131=JCM 32304), Shewanella ulleungensis sp. nov. (type strain, MMS16-UL253=KCTC 62130=JCM 32305) and Shewanella litoralis sp. nov. (type strain, MMS16-UL482=KCTC 62129=JCM 32306) are proposed.
三株革兰氏阴性、非孢子形成、杆状、运动的细菌菌株，分别命名为 MMS16-UL250、MMS16-UL253 和 MMS16-UL482，从沿海海水中分离出来，并进行了分类学鉴定。所有分离株在 4-30°C（最佳温度 25°C）、pH6-10（pH7）和高达 8%NaCl（2.5-4.5%）的条件下生长。三株分离株与最接近的种希瓦氏菌属 algicola St-6 的 16S rRNA 基因序列相似性为 98.1-99.2%，而三株分离株之间的相似性为 98.5-99.0%。在系统发育树中，MMS16-UL250 与 St-6 聚为一簇，但两株菌之间的 DNA-DNA 相关性为 28.8±1.5%，证实了它们在种水平上的分离。另外两株菌分别形成了单独的进化分支。所有菌株的主要醌类为 Q-7、Q-8、MK-7 和 MMK-7，这是希瓦氏菌属的典型特征。所有菌株的主要极性脂均为磷脂酰甘油和磷脂酰乙醇胺，共同的主要脂肪酸是由 C16:1ω7c 和/或 C16:1ω6c 组成的总和特征，而三个菌株之间的比例有所不同。菌株的 DNA G+C 含量也在 42.1-43.7 mol%之间变化。表型特征将每个菌株与 algicola 以及彼此区分开来。基于多相分析，每个菌株都被认为代表了希瓦氏菌属的一个新种，分别命名为 Shewanellasaliphila sp. nov.（模式菌株，MMS16-UL250=KCTC 62131=JCM 32304）、UlleungensisShewanella sp. nov.（模式菌株，MMS16-UL253=KCTC 62130=JCM 32305）和 LitoralisShewanella sp. nov.（模式菌株，MMS16-UL482=KCTC 62129=JCM 32306）。
