Poly-3-hydroxybutyrate production from acetate by recombinant Pseudomonas stutzeri with blocked L-leucine catabolism and enhanced growth in acetate

Jieni Zhu; Wei Liu; Mengjiao Wang; Haiyan Di; Chuanjuan Lü; Ping Xu; Chao Gao; Cuiqing Ma

doi:10.3389/fbioe.2023.1297431

Poly-3-hydroxybutyrate production from acetate by recombinant Pseudomonas stutzeri with blocked L-leucine catabolism and enhanced growth in acetate

Front Bioeng Biotechnol. 2023 Nov 8:11:1297431. doi: 10.3389/fbioe.2023.1297431. eCollection 2023.

Authors

Jieni Zhu¹, Wei Liu¹, Mengjiao Wang¹, Haiyan Di¹, Chuanjuan Lü¹, Ping Xu², Chao Gao¹, Cuiqing Ma¹

Affiliations

¹ State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
² State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China.

Abstract

Acetate is a low-cost feedstock for the production of different bio-chemicals. Electrochemical reduction of CO₂ into acetate and subsequent acetate fermentation is a promising method for transforming CO₂ into value-added chemicals. However, the significant inhibitory effect of acetate on microbial growth remains a barrier for acetate-based biorefinery. In this study, the deletion of genes involved in L-leucine degradation was found to be beneficial for the growth of Pseudomonas stutzeri A1501 in acetate. P. stutzeri (Δpst_3217), in which the hydroxymethylglutaryl-CoA lyase catalyzing β-hydroxy-β-methylglutaryl-CoA into acetyl-CoA and acetoacetate was deleted, grew faster than other mutants and exhibited increased tolerance to acetate. Then, the genes phbCAB from Ralstonia eutropha H16 for poly-3-hydroxybutyrate (PHB) biosynthesis were overexpressed in P. stutzeri (∆pst_3217) and the recombinant strain P. stutzeri (∆pst_3217-phbCAB) can accumulate 0.11 g L^-1 PHB from commercial acetate. Importantly, P. stutzeri (∆pst_3217-phbCAB) can also use CO₂-derived acetate to produce PHB and the accumulated PHB accounted for 5.42% (w/w) of dried cell weight of P. stutzeri (∆pst_3217-phbCAB).

Keywords: CO2; L-leucine catabolism; Pseudomonas stutzeri; acetate; poly-3-hydroxybutyrate.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants from the National Key R&D Program of China (2022YFC2106000), National Natural Science Foundation of China (31970055 and 31970056), and Natural Science Foundation of Shandong Provincial (ZR2020MC005).