Rerouting cellular electron flux to increase the rate of biological methane production

Jennie L. Catlett, Alicia M. Ortiz, Nicole R Buan

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Methanogens are anaerobic archaea that grow by producing methane, a gas that is both an efficient renewable fuel and a potent greenhouse gas. We observed that overexpression of the cytoplasmic heterodisulfide reductase enzyme HdrABC increased the rate of methane production from methanol by 30% without affecting the growth rate relative to the parent strain. Hdr enzymes are essential in all known methane-producing archaea. They function as the terminal oxidases in the methanogen electron transport system by reducing the coenzymeM(2-mercaptoethane sulfonate) and coenzyme B (7-mercaptoheptanoylthreonine sulfonate) heterodisulfide, CoM-S-S-CoB, to regenerate the thiol-coenzymes for reuse. In Methanosarcina acetivorans, HdrABC expression caused an increased rate of methanogenesis and a decrease in metabolic efficiency on methylotrophic substrates. When acetate was the sole carbon and energy source, neither deletion nor overexpression of HdrABC had an effect on growth or methane production rates. These results suggest that in cells grown on methylated substrates, the cell compensates for energy losses due to expression of HdrABC with an increased rate of substrate turnover and that HdrABC lacks the appropriate electron donor in acetate-grown cells.

Original languageEnglish (US)
Pages (from-to)6528-6537
Number of pages10
JournalApplied and environmental microbiology
Volume81
Issue number19
DOIs
StatePublished - Jan 1 2015

Fingerprint

Methane
methane production
methanogens
coenzymes
sulfonates
methane
electrons
Electrons
Archaea
electron
sulfonate
acetates
substrate
acetate
Acetates
Gases
Methanosarcina
energy
cells
enzyme

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

Cite this

Rerouting cellular electron flux to increase the rate of biological methane production. / Catlett, Jennie L.; Ortiz, Alicia M.; Buan, Nicole R.

In: Applied and environmental microbiology, Vol. 81, No. 19, 01.01.2015, p. 6528-6537.

Research output: Contribution to journalArticle

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