Abstract
Denitrification plays a central role in the global nitrogen cycle, reducing and removing nitrogen from marine and terrestrial ecosystems. The flux of nitrogen species through this pathway has a widespread impact, affecting ecological carrying capacity, agriculture, and climate. Nitrite reductase (Nir) and nitric oxide reductase (NOR) are the two central enzymes in this pathway. Here we present a previously unreported Nir domain architecture in members of phylum Chloroflexi. Phylogenetic analyses of protein domains within Nir indicate that an ancestral horizontal transfer and fusion event produced this chimeric domain architecture. We also identify an expanded genomic diversity of a rarely reported NOR subtype, eNOR. Together, these results suggest a greater diversity of denitrification enzyme arrangements exist than have been previously reported.
Highlights
Have the genomic capacity to perform complete denitrification (Figure 1), reducing nitrate to dinitrogen gas
While cytochrome‐type nitric oxide reductase (cNOR) observed in Pseudomonas aeruginosa, cytochrome cd1 catalyzes are only found in denitrifying microbes, other types of nitric oxide reductases (NORs)—for the oxidation of a colocalized cytochrome c551 to reduce nitrite example, quinol‐dependent quinol‐dependent nitric oxide reductases (qNOR)—are found in nondenitrifiers and to nitric oxide (NO) at the heme d1 site (Philippot, 2002; Zumft, 1997)
Acterized in limited members of the Proteobacteria, Firmicutes, These findings suggest that the evolution and/or biochemistry of Archaea, and Chloroflexi (Hemp & Gennis, 2008; Hemp denitrification may be unusual for this subset of bacteria, and et al, 2015; Sievert et al, 2008; Stein et al, 2007)
Summary
Have the genomic capacity to perform complete denitrification (Figure 1), reducing nitrate to dinitrogen gas Collection of all fluid samples and total genomic DNA extractions occurrence of denitrification pathway genes appears to vary across from those fluids, as well as corresponding physical and different taxa and environments (Graf et al, 2014). Some of this geochemical data, have been described previously Sembled from deep‐subsurface MAG data (Jungbluth et al, 2017; Momper & Jungbluth, 2017; Table A5)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
