USCR Bactériologie Moléculaire Génomique, Institut National des Sciences Appliquées et de Technologie, Université de Carthage, Carthage, Tunisia.
LR Écologie Pastorale, Institut des Régions Arides, Médenine, Tunisia.
Int J Syst Evol Microbiol. 2023 Nov;73(11). doi: 10.1099/ijsem.0.006178.
A comprehensive polyphasic investigation was conducted to elucidate the taxonomic position of an actinobacterium, designated BMG 814, which was isolated from the historic ruins of Carthage city in Tunisia. It grew as pink-orange pigmented colonies and displayed versatile growth capabilities, thriving within a temperature range of 20-40 °C, across a pH spectrum ranging from pH 5.5 to 10 and in the presence of up to 4 % NaCl. Chemotaxonomic investigations unveiled specific cell components, including diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, glycophosphatidylinositol, an unidentified aminoglycophospholipid, six unidentified aminolipids, two unidentified phospholipids and one unidentified lipid in its polar lipid profile. Furthermore, galactose, glucose and ribose were identified as the primary cell-wall sugars. Major menaquinones identified were MK-9(H), MK-9(H) and MK-9, while major fatty acids comprised iso-C, iso-C, C 8 and C 9. Through phylogenetic analysis based on the 16S rRNA gene sequence, the strain was positioned within the genus , with BMG 804 showing the closest relationship (99.1 %). In light of this, draft genomes for both strains, BMG 814 and BMG 804, were sequenced in this study, and comparative analysis revealed that strain BMG 814 exhibited digital DNA-DNA hybridization and average nucleotide identity values below the recommended thresholds for demarcating new species with all available genomes of type strains of validly names species. Based on the polyphasic taxonomy assessment, strain BMG 814 (=DSM 46848=CECT 8878) was proposed as the type strain of a novel species named sp. nov.
进行了全面的多相研究,以阐明从突尼斯迦太基市历史遗迹中分离出的放线菌 BMG 814 的分类地位。它生长为粉红色橙色着色的菌落,表现出多种生长能力,在 20-40°C 的温度范围内、pH 值范围为 5.5 到 10 以及高达 4%NaCl 的存在下茁壮成长。化学分类学研究揭示了特定的细胞成分,包括双磷脂酰甘油、磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇、糖基磷脂酰肌醇、一种未鉴定的氨基糖磷脂、六种未鉴定的氨基脂、两种未鉴定的磷脂和一种极性脂中的未鉴定脂质。此外,鉴定出的主要细胞壁糖为半乳糖、葡萄糖和核糖。主要的menaquinones 鉴定为 MK-9(H)、MK-9(H)和 MK-9,而主要的脂肪酸由 iso-C、iso-C、C 8 和 C 9 组成。通过基于 16S rRNA 基因序列的系统发育分析,该菌株位于属内,与 BMG 804 菌株关系最密切(99.1%)。有鉴于此,本研究对这两个菌株,即 BMG 814 和 BMG 804,进行了基因组测序,并通过比较分析发现,菌株 BMG 814 的数字 DNA-DNA 杂交和平均核苷酸同一性值低于有效命名种的所有类型菌株的有效种的可用基因组的建议阈值,表明其无法被定义为一个新的种。基于多相分类学评估,将菌株 BMG 814(=DSM 46848=CECT 8878)提议为一种新种的模式菌株,命名为 sp. nov.。