Generation of a membrane potential by Lactococcus lactis through aerobic electron transport.

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Brooijmans RJ, Poolman B, Schuurman-Wolters GK, de Vos WM, Hugenholtz J

Generation of a membrane potential by Lactococcus lactis through aerobic electron transport.

J Bacteriol. 2007 Jul;189(14):5203-9. Epub 2007 May 11.

PubMed ID

17496098 [ View in PubMed

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Abstract

Lactococcus lactis, a facultative anaerobic lactic acid bacterium, is known to have an increased growth yield when grown aerobically in the presence of heme. We have now established the presence of a functional, proton motive force-generating electron transfer chain (ETC) in L. lactis under these conditions. Proton motive force generation in whole cells was measured using a fluorescent probe (3',3'-dipropylthiadicarbocyanine), which is sensitive to changes in membrane potential (Delta psi). Wild-type cells, grown aerobically in the presence of heme, generated a Delta psi even in the presence of the F(1)-F(o) ATPase inhibitor N,N'-dicyclohexylcarbodiimide, while a cytochrome bd-negative mutant strain (CydA Delta) did not. We also observed high oxygen consumption rates by membrane vesicles prepared from heme-grown cells, compared to CydA Delta cells, upon the addition of NADH. This demonstrates that NADH is an electron donor for the L. lactis ETC and demonstrates the presence of a membrane-bound NADH-dehydrogenase. Furthermore, we show that the functional respiratory chain is present throughout the exponential and late phases of growth.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
NADH	NADH dehydrogenase [ubiquinone] 1 subunit C2	Protein	Humans	Unknown	Not Available	Details