Artuso Irene, Turrini Paolo, Pirolo Mattia, Lugli Gabriele Andrea, Ventura Marco, Visca Paolo
Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy.
Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark.
Microorganisms. 2021 Jun 19;9(6):1332. doi: 10.3390/microorganisms9061332.
Bacteria belonging to the genus are metabolically versatile organisms thriving in both natural and anthropized terrestrial environments. To date, the taxonomy of this genus is poorly defined due to the unavailability of the genomic sequence of LMG 26462 and the presence of unclassified strains. Here, we determined the genome sequence of LMG 26462 and performed phylogenomic, average nucleotide identity and digital DNA-DNA hybridization analyses of 17 members of genus . Our results indicate that 16S rRNA-based phylogeny does not provide sufficient species-level discrimination, since most of the unclassified strains belong to valid species or are putative new species. Since some members of the genus can utilize certain C1 compounds, such as methylamines and methyl halides, a comparative genomic analysis was performed to characterize the genetic basis of some degradative/assimilative pathways in the whole genus. Our findings suggest that all species are heterotrophic methylotrophs able to generate the methylene tetrahydrofolate intermediate through multiple oxidative pathways of C1 compounds and convey it in the serine cycle. Moreover, all species carry genes implicated in the degradation of phosphonates via the C-P lyase pathway, whereas only LMG 26462 contains a symbiosis island implicated in nodulation and nitrogen fixation.
属于该属的细菌是代谢多样的生物,在自然和人为的陆地环境中都能茁壮成长。迄今为止,由于缺乏LMG 26462的基因组序列以及存在未分类的菌株,该属的分类学定义尚不明确。在这里,我们确定了LMG 26462的基因组序列,并对该属的17个成员进行了系统基因组学、平均核苷酸同一性和数字DNA-DNA杂交分析。我们的结果表明,基于16S rRNA的系统发育不能提供足够的物种水平区分,因为大多数未分类的菌株属于有效的物种或可能是新物种。由于该属的一些成员可以利用某些C1化合物,如甲胺和卤代甲烷,因此进行了比较基因组分析,以表征整个属中一些降解/同化途径的遗传基础。我们的研究结果表明,所有物种都是异养甲基营养菌,能够通过C1化合物的多种氧化途径生成亚甲基四氢叶酸中间体,并在丝氨酸循环中传递它。此外,所有物种都携带通过C-P裂解酶途径参与膦酸盐降解的基因,而只有LMG 26462含有一个与结瘤和固氮有关的共生岛。