AUTHOR=Cortés-Albayay Carlos , Sangal Vartul , Klenk Hans-Peter , Nouioui Imen 

TITLE=Comparative Genomic Study of Vinyl Chloride Cluster and Description of Novel Species, Mycolicibacterium vinylchloridicum sp. nov.

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.767895

DOI=10.3389/fmicb.2021.767895

ISSN=1664-302X

ABSTRACT=<p>Advanced physicochemical and chemical absorption methods for chlorinated ethenes are feasible but incur high costs and leave traces of pollutants on the site. Biodegradation of such pollutants by anaerobic or aerobic bacteria is emerging as a potential alternative. Several mycobacteria including <italic>Mycolicibacterium aurum</italic> L1, <italic>Mycolicibacterium chubuense</italic> NBB4, <italic>Mycolicibacterium rhodesiae</italic> JS60, <italic>Mycolicibacterium rhodesiae</italic> NBB3 and <italic>Mycolicibacterium smegmatis</italic> JS623 have previously been described as assimilators of vinyl chloride (VC). In this study, we compared nucleotide sequence of VC cluster and performed a taxogenomic evaluation of these mycobacterial species. The results showed that the complete VC cluster was acquired by horizontal gene transfer and not intrinsic to the genus <italic>Mycobacterium sensu lato</italic>. These results also revealed the presence of an additional <italic>xcb</italic>F1 gene that seems to be involved in Coenzyme M biosynthesis, which is ultimately used in the VC degradation pathway. Furthermore, we suggest for the first time that S/N-Oxide reductase encoding gene was involved in the dissociation of the SsuABC transporters from the organosulfur, which play a crucial role in the Coenzyme M biosynthesis. Based on genomic data, <italic>M. aurum</italic> L1, <italic>M. chubuense</italic> NBB4<italic>, M. rhodesiae</italic> JS60, <italic>M. rhodesiae</italic> NBB3 and <italic>M. smegmatis</italic> JS623 were misclassified and form a novel species within the genus <italic>Mycobacterium sensu lato</italic>. <italic>Mycolicibacterium aurum</italic> L1<sup>T</sup> (CECT 8761<sup>T</sup> = DSM 6695<sup>T</sup>) was the subject of polyphasic taxonomic studies and showed ANI and dDDH values of 84.7 and 28.5% with its close phylogenetic neighbour, <italic>M. sphagni</italic> ATCC 33027<sup>T</sup>. Phenotypic, chemotaxonomic and genomic data considering strain L1<sup>T</sup> (CECT 8761<sup>T</sup> = DSM 6695<sup>T</sup>) as a type strain of novel species with the proposed name, <italic>Mycolicibacterium vinylchloridicum</italic> sp. nov.</p>