Identification of Exiguobacterium artemiae Strains Tolerant to Xenobiotics in Wastewater from the Bogota River, Colombia

The Bogotá River receives a large amount of domestic and industrial wastewater, which has significant ecological impacts. Although these effluents charge several bacteria that represent a risk to human, animal, and vegetable health, some species can also resist high concentrations of contaminants. This study aimed to investigate the microbial diversity present in the wastewater of the Bogotá River through metataxonomic analysis. Additionally, the tolerance of a strain of Exiguobacterium artemiae isolated from these waters to xenobiotics was evaluated. The results showed a clear predominance of the phylum Proteobacteria. At the family level, the most prominent were Moraxellaceae, Comamonadaceae and Rhodobacteraceae, while at the genus level, Acinetobacter predominated over the other genera. Three bacterial isolates numbered 10, 13, and 18 were evaluated for their ability to grow in media supplemented with heavy metals such as chromo (Cr), cobalt (Co), cadmium (Cd), nickel (Ni), and several textile dyes. All three isolates grew in the presence of heavy metals and textile dyes, highlighting isolate number 13 for higher resistance to Co and Cr and isolate 18 for Co and Ni. Isolate 18 was identified via WGS as a strain related to Exiguobacterium artemiae 255-15, with 94.4% similarity. Genes and pathways associated with xenobiotic degradation routes, mainly aromatic compounds, EthD family reductases, FMN-dependent NADH-azoreductases, and chromate efflux transporters, were identified, suggesting their potential in the bioremediation of water contaminated with xenobiotics.

Keywords:
Pollution; whole-genome sequencing; Exiguobacterium artemiae; xenobiotics; efflux pumps.

Severe pollution from wastewater harms the Bogotá River

Proteobacteria was the most abundant phyla in the Bogotá River.

Proteobacteria Firmicutes and Bacteroidota were the most abundant phyla in the Bogotá River

Exiguobacterium artemiae has genetic mechanism to resist heavy metal toxicity and other xenobiotics.

Exiguobacterium artemiae is a potential bioremediation candidate due to its resilience and detoxofication.