Alternative oxidation pathways in the respiratory chain of Brevibacterium flavum
Shvinka, I.E.; Viestur, U.E.; Toma, M.K.
Mikrobiologiia 48(1): 10-16
1979
ISSN/ISBN: 0026-3656 PMID: 218084 Document Number: 150171
A scheme is proposed for the branched respiratory chain in B. flavum 22 LD. Three branching sites in the main electron transport pathway are suggested: at the initial stage of NADH2 oxidation (before menaquinone) and at the levels of cytochromes b and c. Up to 40% of the total O2 is consumed in the NADH2-dependent alternative oxidative pathway in the presence of 5 .cntdot. 10-3 M cyanide or after the near-UV treatment. This bypass differs from the main electron flow with a lower P/O ratio. Exogenous NADH2 catalyzes the univalent reduction of O2 through superoxide production in the bacterial membranes. Alternative oxidation pathways are discussed regarding their regulatory role in bacterial energy metabolism.