Reconstruction of tricarboxylic acid cycle in Corynebacterium glutamicum with a genome ‐scale metabolic network model for trans‐4‐hydroxyproline production

The TCA cycle inCorynebacterium glutamicum was reconstructed by inactivating succinyl ‐CoA synthetase to redirect α‐ketoglutarate toward proline hydroxylation. P4H bridged the broken TCA cycle through the conversion of cosubstrate α‐ketoglutarate to succinate and led to a significant increase in Hyp production. Fine‐tuning of ProB* and P4H abundances gave rise to the improv ement in the yield of Hyp on glucose. Abstracttrans‐4‐Hydroxy‐l‐proline (Hyp) is an abundant component of mammalian collagen and functions as a chiral synthon for the syntheses of anti‐inflammatory drugs in the pharmaceutical industry. Proline 4‐hydroxylase (P4H) can catalyze the conversion ofl‐proline to Hyp; however, it is still challenging for the fermentative production of Hyp from glucose using P4H due to the low yield and productivity. Here, we report the metabolic engineering ofCorynebacterium glutamicum for the fermentative production of Hyp by reconstructing tricarboxylic acid (TCA) cycle together with heterologously expressing thep4h gene fromDactylosporangium sp. strain RH1. In silico model ‐based simulation showed that α‐ketoglutarate was redirected from the TCA cycle toward Hyp synthetic pathway driven by P4H when the carbon flux from succinyl‐CoA to succinate descended to zero. The interruption of the TCA cycle by the deletion ofsucCD‐encoding the succinyl‐CoA synthetase (SUCOAS) led to a 60% increase in Hyp production and had no obvious impact on the growth...
Source: Biotechnology and Bioengineering - Category: Biomedical Science Authors: Tags: ARTICLE Source Type: research