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Improving protein secretion of a transglutaminase-secreting Corynebacterium glutamicum recombinant strain on the basis of 13C metabolic flux analysis

Paper ID Volume ID Publish Year Pages File Format Full-Text
20939 43198 2011 7 PDF Available
Title
Improving protein secretion of a transglutaminase-secreting Corynebacterium glutamicum recombinant strain on the basis of 13C metabolic flux analysis
Abstract

Corynebacterium glutamicum is known as a host species for amino acid production. This microorganism was recently noticed as a host that produces secreted proteins. In this study, we performed 13C metabolic flux analysis (13C-MFA) on a recombinant C. glutamicum strain that secretes a heterologous transglutaminase (TGase) to improve TGase secretion. For the 13C-MFA of a TGase-secreting C. glutamicum strain in batch cultivation, a 13C-labeling experiment and measurement of mass isotopomer distributions of proteinogenic amino acids were performed, and metabolic fluxes were determined considering the changes in fractional 13C-labeling of proteinogenic amino acids with respect to culture time. The TGase yield increased at the stationary phase but decreased toward its end. The results of 13C-MFA revealed that the flux from glycolysis to the TCA cycle gradually increased during TGase secretion. We speculate that the NADH/NAD+ ratio in the cells increases and that as a result, the specific glucose uptake rate decreases in the stationary phase because of the increased flux of the TCA cycle. Since it is expected that a decrease in the NADH/NAD+ ratio would improve the TGase yield, we tried to enhance lactate production in a TGase-secreting C. glutamicum strain to decrease cellular NADH levels by increasing the pH level in the culture. The TGase yield increased in 1.4-fold by increasing the pH from 6.7 to 7.2, indicating that the TGase yield was successfully improved on the basis of the 13C-MFA.

Keywords
Corynebacterium glutamicum; 13C metabolic flux analysis; Protein secretion; Transglutaminase; Batch cultivation; NADH/NAD+ ratio
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Improving protein secretion of a transglutaminase-secreting Corynebacterium glutamicum recombinant strain on the basis of 13C metabolic flux analysis
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 112, Issue 6, December 2011, Pages 595–601
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
Online Support
Any Questions? feel free to contact us