Article
Novel arsenic-transforming bacteria and the diversity of their arsenic-related genes and enzymes arising from arsenic-polluted freshwater sediment
Registro en:
SUHADOLNIK, Maria Luiza S. et al. Novel arsenic-transforming bacteria and the diversity of their arsenic-related genes and enzymes arising from arsenic-polluted freshwater sediment. Sci Rep. , v. 7, n. 1, art. 11231, 2017
2045-2322
Autor
Suhadolnik, Maria Luiza S.
Salgado, Ana Paula Lima C
Scholte, Larissa Lopes Silva
Bleicher, Lucas
Costa, Patrícia S.
Reis, Mariana P.
Dias, Marcela F.
Ávila, Marcelo P.
Barbosa, Francisco A. R.
Souza, Edmar Chartone
Nascimento, Andréa Maria Amaral
Resumen
Bacteria are essential in arsenic cycling. However, few studies have addressed 16S rRNA and arsenicrelated functional gene diversity in long-term arsenic-contaminated tropical sediment. Here, using culture-based, metagenomic and computational approaches, we describe the diversity of bacteria, genes and enzymes involved in AsIII and AsV transformation in freshwater sediment and in anaerobic AsIII- and AsV-enrichment cultures (ECs). The taxonomic profle reveals signifcant diferences among the communities. Arcobacter, Dechloromonas, Sedimentibacter and Clostridium thermopalmarium were exclusively found in ECs, whereas Anaerobacillus was restricted to AsV-EC. Novel taxa that are both AsV-reducers and AsIII-oxidizers were identifed: Dechloromonas, Acidovorax facilis, A. delafeldii, Aquabacterium, Shewanella, C. thermopalmarium and Macellibacteroides fermentans. Phylogenic discrepancies were revealed among the aioA, arsC and arrA genes and those of other species, indicating horizontal gene transfer. ArsC and AioA have sets of amino acids that can be used to assess their functional and structural integrity and familial subgroups. The positions required for AsV reduction are conserved, suggesting strong selective pressure for maintaining the functionality of ArsC. Altogether, these fndings highlight the role of freshwater sediment bacteria in arsenic mobility, and the untapped diversity of dissimilatory arsenate-reducing and arsenate-resistant bacteria, which might contribute to arsenic toxicity in aquatic environments 2022-01-01