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Improved L-ornithine production in Corynebacterium crenatum by introducing an artificial linear transacetylation pathway.

Improved L-ornithine production in Corynebacterium crenatum by introducing an artificial linear transacetylation pathway.

Authors :
Shu, Qunfeng
Xu, Meijuan
Li, Jing
Yang, Taowei
Zhang, Xian
Xu, Zhenghong
Rao, Zhiming
Source :
Journal of Industrial Microbiology & Biotechnology. Jun2018, Vol. 45 Issue 6, p393-404. 12p. 1 Black and White Photograph, 1 Diagram, 4 Charts, 3 Graphs.
Publication Year :
2018

Abstract

L-Ornithine is a non-protein amino acid with extensive applications in the food and pharmaceutical industries. In this study, we performed metabolic pathway engineering of an L-arginine hyper-producing strain of Corynebacterium crenatum for L-ornithine production. First, we amplified the L-ornithine biosynthetic pathway flux by blocking the competing branch of the pathway. To enhance L-ornithine synthesis, we performed site-directed mutagenesis of the ornithine-binding sites to solve the problem of L-ornithine feedback inhibition for ornithine acetyltransferase. Alternatively, the genes argA from Escherichia coli and argE from Serratia marcescens, encoding the enzymes N-acetyl glutamate synthase and N-acetyl-L-ornithine deacetylase, respectively, were introduced into Corynebacterium crenatum to mimic the linear pathway of L-ornithine biosynthesis. Fermentation of the resulting strain in a 5-L bioreactor allowed a dramatically increased production of L-ornithine, 40.4 g/L, with an overall productivity of 0.673 g/L/h over 60 h. This demonstrates that an increased level of transacetylation is beneficial for L-ornithine biosynthesis. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
13675435
Volume :
45
Issue :
6
Database :
Academic Search Index
Journal :
Journal of Industrial Microbiology & Biotechnology
Publication Type :
Academic Journal
Accession number :
130552575
Full Text :
https://doi.org/10.1007/s10295-018-2037-1