León María José, Sánchez-Porro Cristina, Ventosa Antonio
Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain.
Int J Syst Evol Microbiol. 2017 Aug;67(8):2622-2627. doi: 10.1099/ijsem.0.001984. Epub 2017 Aug 10.
A moderately halophilic bacterium designated strain M6-53T was isolated from water of a pond from a marine saltern located in Huelva, south-west Spain. Cells of the strain were Gram-stain-negative, strictly aerobic, motile, slightly curved rods, able to grow in media containing 5-25 % (w/v) NaCl (optimal growth at 10 %, w/v), at temperatures from 20 to 40 °C (optimally at 37 °C) and at pH 6.5-9 (optimally at pH 7.0). Phylogenetic analysis based on 16S rRNA gene sequences placed the new isolate within the genus Marinobacter, with the type strains of the most closely related species being Marinobacter persicus IBRC-M 10445T (98.5 % similarity), Marinobacter oulmenensis Set74T (97.2 %) and Marinobacter hydrocarbonoclasticus ATCC 49840T (97.1 %). The major fatty acids present in strain M6-53T were C18 : 1ω9c (29.5 %), C16 : 0 (26.7 %), C12 : 0 3-OH (15.1 %), C18 : 0 (10.2 %) and C16 : ω9c (9.6 %). The G+C content of the genomic DNA for this strain was determined to be 56.4 mol%. The DNA-DNA hybridization values between strain M6-53T and M. persicus CECT 7991T, M. oulmenensis CECT 7499T and M. hydrocarbonoclasticus DSM 50418 were 8, 41 and 38 %, respectively. These values are lower than the accepted 70 % threshold and showed that the new isolate represented a different species within the genus Marinobacter. Phylogenetic analysis based on the 16S rRNA gene sequence and the phenotypic, genotypic and chemotaxonomic features of this new isolate support the placement of strain M6-53T as a representative of a novel species of the genus Marinobacter, for which we propose the name Marinobacter aquaticus sp. nov., with strain M6-53T (=CECT 9228T=LMG 30006T) as the type strain.
从西班牙西南部韦尔瓦市一个海水盐场的池塘水中分离出一株中度嗜盐细菌，命名为菌株M6-53T。该菌株细胞革兰氏染色阴性，严格需氧，具运动性，呈微弯杆状，能在含有5-25%（w/v）NaCl的培养基中生长（最适生长浓度为10%，w/v），生长温度为20至40°C（最适温度为37°C），pH值为6.5-9（最适pH值为7.0）。基于16S rRNA基因序列的系统发育分析表明，该新分离菌株属于海杆菌属，与最密切相关物种的模式菌株海杆菌（Marinobacter persicus）IBRC-M 10445T（相似度98.5%）、欧尔门海杆菌（Marinobacter oulmenensis）Set74T（相似度97.2%）和烃解海杆菌（Marinobacter hydrocarbonoclasticus）ATCC 49840T（相似度97.1%）聚在一起。菌株M6-53T中的主要脂肪酸为C18:1ω9c（29.5%）、C16:0（26.7%）、C12:0 3-OH（15.1%）、C18:0（10.2%）和C16:ω9c（9.6%）。该菌株基因组DNA的G+C含量测定为56.4 mol%。菌株M6-53T与海杆菌CECT 7991T、欧尔门海杆菌CECT 7499T和烃解海杆菌DSM 50418之间的DNA-DNA杂交值分别为8%、41%和38%。这些值低于公认的70%阈值，表明该新分离菌株代表海杆菌属内的一个不同物种。基于16S rRNA基因序列的系统发育分析以及该新分离菌株的表型、基因型和化学分类学特征支持将菌株M6-53T归为海杆菌属一个新物种的代表，我们将其命名为水生海杆菌（Marinobacter aquaticus）新种，以菌株M6-53T（=CECT 9228T=LMG 30006T）作为模式菌株。
