Improving 3-hydroxypropionic acid production in E. coli by in silico prediction of new metabolic targets.

Autor: Chaves GL; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., Batista RS; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., Cunha JS; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., Oliveira DB; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., da Silva MR; Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970 Campinas, SP, Brazil., Pisani GFD; Department of Physiological Sciences, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., Selistre-de-Araújo HS; Department of Physiological Sciences, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., Zangirolami TC; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil., da Silva AJ; Graduate Program of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luís, km 235, São Carlos, SP 13565-905, Brazil. Electronic address: adilsonjs@ufscar.br.
Jazyk: angličtina
Zdroj: New biotechnology [N Biotechnol] 2022 Dec 25; Vol. 72, pp. 80-88. Date of Electronic Publication: 2022 Oct 19.
DOI: 10.1016/j.nbt.2022.10.002
Abstrakt: 3-Hydroxypropionic acid (3-HP) production from renewable feedstocks is of great interest in efforts to develop greener processes for obtaining this chemical platform. Here we report an engineered E. coli strain for 3-HP production through the β-alanine pathway. To obtain a new strain capable of producing 3-HP, the pathway was established by overexpressing the enzymes pyruvate aminotransferase, 3-hydroxyacid dehydrogenase, and L-aspartate-1-decarboxylase. Further increase of the 3-HP titer was achieved using evolutionary optimizations of a genome-scale metabolic model of E. coli containing the adopted pathway. From these optimizations, three non-intuitive targets for in vivo assessment were identified: L-alanine aminotransferase and alanine racemase overexpression, and L-valine transaminase knock-out. The implementation of these targets in the production strain resulted in a 40% increase in 3-HP titer. The strain was further engineered to overexpress phosphoenolpyruvate carboxylase, reaching 0.79 ± 0.02 g/L of 3-HP when grown using glucose. Surprisingly, this strain produced 63% more of the desired product when grown using a mixture of glucose and xylose (1:1, C-mol), and gene expression analysis showed that the cellular adjustment to consume xylose had a positive impact on 3-HP accumulation. Fed-batch culture with xylose feeding led to a final titer of 29.1 g/L. These results reinforce the value of computational methods in strain engineering, enabling the design of more efficient strategies to be assessed. Moreover, higher production of 3-HP under a sugar mixture condition points towards the development of bioprocesses based on renewable resources, such as hemicellulose hydrolysates.
Competing Interests: Conflicts of interests The authors declare no conflicts of interest.
(Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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