Abstract
l-Leucine is an important essential amino acid with multiple industrial applications, whose market requirements cannot be met because of the low productivity. In this study, a strain of Corynebacterium glutamicum with high l-leucine yield was constructed to enhance its acetyl-CoA supply and glucose utilization. One copy of leuA under the control of a strong promoter was incorporated into the C. glutamicum genome. Then, acetyl-CoA supply was increased by the integration of a terminator in front of gltA and by the heterogeneous overexpression of acetyl-CoA synthetase (ACS) and deacetylase (CobB) derived from Escherichia coli. Next, the transcriptional regulator sugR was deleted to enhance glucose uptake via a phosphotransferase-mediated route. In fed-batch fermentation performed in a 5-L reactor, l-leucine production of 40.11 ± 0.73g L-1 was achieved under the optimized conditions, with an l-leucine yield and productivity of 0.25g g-1 glucose and 0.59g L-1 h-1 , respectively. These results represent a significant improvement in the l-leucine production of C. glutamicum, indicating that the process possesses high potential for industrial application. These strategies can be also expanded to enable the production of other value-added biochemicals derived from the intermediates of central carbon metabolism.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call