Departamento de Microbiología y Ecología, Colección Española de Cultivos Tipo (CECT), Universidad de Valencia, Valencia, Spain.
Int J Syst Evol Microbiol. 2012 Apr;62(Pt 4):844-848. doi: 10.1099/ijs.0.030973-0. Epub 2011 May 20.
Strain MD5T, an aerobic marine alphaproteobacterium, was isolated from Mediterranean seawater at Malvarrosa beach, Valencia, Spain. The strain was characterized in a polyphasic study and was placed phylogenetically within the Roseobacter clade in the family Rhodobacteraceae. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MD5T is related to Tropicibacter naphthalenivorans C02T, Phaeobacter inhibens T5T, P. gallaeciensis BS107T and P. daeponensis TF-218T, with 96.9, 96.2, 96.1 and 96.1 % sequence similarity, respectively. Phylogenetic analyses also showed that strain MD5T forms a stable clade only with T. naphthalenivorans C02T. Strain MD5T requires Na+ plus a divalent cation (either Mg2+ or Ca2+) to grow, does not reduce nitrate to nitrite and uses a large number of carbohydrates as sole carbon sources. It is positive for β-galactosidase and urease activities and aesculin hydrolysis. Enzyme activities displayed in the API ZYM strip were alkaline phosphatase, leucine arylamidase, acid phosphatase and α-glucosidase. Major cellular fatty acids were summed feature 8 (C18:1ω7c and/or C18:1ω6c; 70.9 %) and C16:0 (8.2 %). The results of physiological and biochemical tests allowed clear phenotypic differentiation of this isolate from the only described species of the genus Tropicibacter. It is evident from the genotypic and phenotypic data obtained that the strain should be classified in a novel species in the genus Tropicibacter. The name Tropicibacter multivorans sp. nov. is proposed, with the type strain MD5T (=CECT 7557T=KCTC 23350T).
海洋α-变形菌门需氧菌株 MD5T 从西班牙瓦伦西亚马尔瓦罗萨海滩的地中海海水中分离得到。该菌株通过多相研究进行了表征，并在红杆菌科的玫瑰杆菌群中系统发育。基于 16S rRNA 基因序列的系统发育分析表明，菌株 MD5T 与萘烷降解菌 C02T、抑制杆菌 T5T、Phaeobacter gallaeciensis BS107T 和 P. daeponensis TF-218T 关系最为密切，序列相似性分别为 96.9%、96.2%、96.1%和 96.1%。系统发育分析还表明，菌株 MD5T 仅与萘烷降解菌 C02T 形成一个稳定的分支。菌株 MD5T 需要 Na+和一种二价阳离子（Mg2+或 Ca2+）才能生长，不能将硝酸盐还原为亚硝酸盐，并大量使用碳水化合物作为唯一碳源。它对β-半乳糖苷酶和脲酶活性以及马栗树皮苷水解呈阳性。API ZYM 条带显示的酶活性有碱性磷酸酶、亮氨酸芳基酰胺酶、酸性磷酸酶和α-葡萄糖苷酶。主要细胞脂肪酸为 summed feature 8（C18:1ω7c 和/或 C18:1ω6c；70.9%）和 C16:0（8.2%）。生理生化试验结果使该分离株与唯一描述的 Tropicibacter 属物种明显区别开来。从获得的基因型和表型数据来看，该菌株应归类为 Tropicibacter 属的一个新种。建议采用多营养菌 Tropicibacter multivorans sp. nov.，其模式菌株为 MD5T（=CECT 7557T=KCTC 23350T）。
