Hemerythrins enhance aerobic respiration in Methylomicrobium alcaliphilum 20ZR, a methane-consuming bacterium
- Biology Department, 5500 Campanile Drive, San Diego, CA, USA
- Biology Department, 5500 Campanile Drive, San Diego, CA, USA, Viral Information Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA
ABSTRACT Numerous hemerythrins, di-iron proteins, have been identified in prokaryote genomes, but in most cases their function remains elusive. Bacterial hemerythrin homologs (bacteriohemerythrins, Bhrs) may contribute to various cellular functions, including oxygen sensing, metal binding and antibiotic resistance. It has been proposed that methanotrophic Bhrs support methane oxidation by supplying oxygen to a core enzyme, particulate methane monooxygenase. In this study, the consequences of the overexpression or deletion of the Bhr gene (bhr) in Methylomicrobiam alcaliphillum 20ZR were investigated. We found that the bhrknockout (20ZRΔbhr) displays growth kinetics and methane consumption rates similar to wild type. However, the 20ZRΔbhr accumulates elevated concentrations of acetate at aerobic conditions, indicating slowed respiration. The methanotrophic strain overproducing Bhr shows increased oxygen consumption and reduced carbon-conversion efficiency, while its methane consumption rates remain unchanged. These results suggest that the methanotrophic Bhr proteins specifically contribute to oxygen-dependent respiration, while they have minimal, if any, input of oxygen for the methane oxidation machinery.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- FOA-0001085
- OSTI ID:
- 1604246
- Journal Information:
- FEMS Microbiology Letters (Online), Journal Name: FEMS Microbiology Letters (Online) Vol. 367 Journal Issue: 2; ISSN 1574-6968
- Publisher:
- Oxford University PressCopyright Statement
- Country of Publication:
- Netherlands
- Language:
- English
Web of Science
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