Comprehensive insights into arsenic- and iron-redox genes, their taxonomy and associated environmental drivers deciphered by a meta-analysis. (January 2021)

• Record Type: Journal Article
• Authors: Suhadolnik, Maria Luíza S.; Costa, Patrícia S.; Castro, Giovanni M.; Lobo, Francisco P.; Nascimento, Andréa M.A.
• Is Part Of: Environment international. Volume 146(2021)
• Publication Date: 2021-01
• Subjects: Arsenic-redox genes -- Iron-redox genes -- Meta-analysis -- Cytochrome -- Taxonomy -- Diversity -- Geophysicochemical data; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2020.106234
• Languages: English
• ISSNs: 0160-4120

Abstract

Highlights: cco N likely enhances host survival in Fe-limiting environments. iro and ccoN may be associated with As(V) detoxification in mesophilic environments. Cytochromes with putative roles in Fe-redox correlate with As(V) reduction genes. Taxonomic analysis showed unprecedented diversity, especially for arsC and pet C. ars C, pet C and cco N predominate and likely play key roles in As and Fe global cycling. Abstract: In nature, arsenic (As) and iron (Fe) biotransformation are interconnected, influencing local As mobility and toxicity. While As- or Fe-metabolizing microorganisms are widely documented, knowledge concerning their cycling genes, associated with geophysicochemical data and taxonomic distribution, remains scarce. We performed a meta -analysis to explore the distribution and environmental importance of As- and Fe-redox genes (AsRGs and FeRGs) and predict their significant correlations and hosts. The most abundant and ubiquitous AsRGs and FeRGs were ars C and cco N, respectively. The cco N gene had the highest frequency at pH ≥ 9.1, in which dissolved Fe(II) is scarce, possibly contributing to enhanced host survival. Fe(III) oxidation genes iro and cco N appear to be associated with As(V) detoxification in mesophilic environments. No correlation was observed between Fe(III) reduction gene omc B and arsenate reductase genes. Cytochromes with putative roles in Fe-redox reactions were identified (including yce J and fbc H) and were significantly correlated with As(V) reduction genes under diverse geophysicochemical conditions. The taxonomies of AsRGs and FeRGs-carrying contigs revealed great diversity, among which various, such as Chlamydea ( ars C) and Firmicutes ( omc B), were previously undescribed. Nearly all (98.9%) of the AsRGs and FeRGs were not carried by any plasmid sequences. This meta -analysis expands our understanding of the global environmental, taxonomic and functional microbiome involved in As- and Fe-redox transformations. Moreover, these findings should help guide studies on putative in vivo functional roles of cytochromes in Fe-redox pathways.