Ntana Fani, Hennessy Rosanna C, Zervas Athanasios, Stougaard Peter
Department of Environmental Science, Aarhus University, Roskilde, Denmark.
Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Int J Syst Evol Microbiol. 2023 Feb;73(2). doi: 10.1099/ijsem.0.005700.
The bacterial strain In5 was previously isolated from a suppressive potato field in southern Greenland and has been characterized and described as . However, the results of new polyphasic analyses coupled with those of phenotypic, phylogenetic and genomic analyses reported here demonstrate that the affiliation to the species was incorrect. The strain is Gram-stain-negative, rod-shaped, aerobic and displays growth at 4-28 °C (optimum temperature 20-25 °C) and at pH 5-9 (optimum pH 6-7). Major fatty acids were C (38.2 %), a summed feature consisting of Cω6 and/or Cω7) (20.7 %), Ccyclo ω7 (14.3 %) and a summed feature consisting of Cω6 and/or Cω7 (11.7 %). The respiratory quinones were determined to be Q9 (95.5 %) and Q8 (4.5 %) and major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was determined to be 59.4 mol%. The results of phylogenetic analysis based on the 16S rRNA gene and multi-locus sequence analysis (MLSA; concatenated and sequences) indicated that In5 was affiliated with the subgroup within the genus . Comparison of the genome sequence of In5 and those of related type strains of species of the genus revealed an average nucleotide identity (ANI) of 87.7 % or less and digital DNA-DNA hybridization (dDDH) of less than 34.5 % relatedness, respectively. Two more strains, In614 and In655, isolated from the same suppressive soil were included in the genome analysis. The ANI and dDDH of In614 and In655 compared with In5 were ANI: 99.9 and 97.6 and dDDH (GGDC) 99.9 and 79.4, respectively, indicating that In5, In614 and In655 are representatives of the same species. The results of the phenotypic, phylogenetic and genomic analyses support the hypothesis that strain In5 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is In5(=LMG 32653=NCIMB 15428).
菌株In5先前从格陵兰岛南部一块具有病害抑制作用的马铃薯田中分离得到，并已进行了特征描述。然而，本文报道的新的多相分析结果，以及表型、系统发育和基因组分析结果表明，该菌株与该物种的归属关系是错误的。该菌株革兰氏染色阴性，杆状，好氧，在4-28°C（最适温度20-25°C）和pH 5-9（最适pH 6-7）条件下生长。主要脂肪酸为C（38.2%）、一个由Cω6和/或Cω7组成的总和特征（20.7%）、环Cω7（14.3%）以及一个由Cω6和/或Cω7组成的总和特征（11.7%）。呼吸醌确定为Q9（95.5%）和Q8（4.5%），主要极性脂为磷脂酰乙醇胺、磷脂酰甘油和二磷脂酰甘油。DNA G+C含量确定为59.4 mol%。基于16S rRNA基因和多位点序列分析（MLSA；串联的和序列）的系统发育分析结果表明，In5属于该属内的亚组。In5的基因组序列与该属相关模式菌株的基因组序列比较显示，平均核苷酸同一性（ANI）为87.7%或更低，数字DNA-DNA杂交（dDDH）相关性小于34.5%。从同一抑制性土壤中分离得到的另外两个菌株In614和In655也纳入了基因组分析。In614和In655与In5相比的ANI和dDDH分别为：ANI：99.9和97.6，dDDH（GGDC）99.9和79.4，表明In5、In614和In655是同一物种的代表。表型、系统发育和基因组分析结果支持了菌株In5代表该属一个新物种的假设，为此提出新物种名称 sp. nov.。模式菌株为In5（=LMG 32653=NCIMB 15428）。
