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Mechanism of increased respiration in an H+-ATPase-defective mutant of Corynebacterium glutamicum

Paper ID Volume ID Publish Year Pages File Format Full-Text
21308 43216 2012 7 PDF Available
Title
Mechanism of increased respiration in an H+-ATPase-defective mutant of Corynebacterium glutamicum
Abstract

We previously reported that a spontaneous H+-ATPase-defective mutant of Corynebacterium glutamicum, F172-8, derived from C. glutamicum ATCC 14067, showed enhanced glucose consumption and respiration rates. To investigate the genome-based mechanism of enhanced respiration rate in such C. glutamicum mutants, A-1, an H+-ATPase-defective mutant derived from C. glutamicum ATCC 13032, which harbors the same point mutation as F172-8, was used in this study. A-1 showed similar fermentation profiles to F172-8 when cultured in a jar fermentor. Enzyme activity measurements, quantitative real-time PCR, and DNA microarray analysis suggested that A-1 enhanced malate:quinone oxidoreductase/malate dehydrogenase and l-lactate dehydrogenase/NAD+-dependent-lactate dehydrogenase coupling reactions, but not NADH dehydrogenase-II, for reoxidation of the excess NADH arising from enhanced glucose consumption. A-1 also up-regulated succinate dehydrogenase, which may result in the relief of excess proton-motive force (pmf) in the H+-ATPase mutant. In addition, the transcriptional level of cytochrome bd oxidase, but not cytochrome bc1-aa3, also increased, which may help prevent the excess pmf generation caused by enhanced respiration. These results indicate that C. glutamicum possesses intriguing strategies for coping with NADH over-accumulation. Furthermore, these mechanisms are different from those in Escherichia coli, even though the two species use similar strategies to prevent excess pmf generation.

Keywords
Corynebacterium glutamicum; H+-ATPase defect; Respiratory chain; NADH reoxidation; Energy metabolism; Energy deficiency
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Mechanism of increased respiration in an H+-ATPase-defective mutant of Corynebacterium glutamicum
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 113, Issue 4, April 2012, Pages 467–473
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
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Any Questions? feel free to contact us