Enhanced supply of acetyl-CoA by exogenous pantothenate kinase promotes synthesis of poly(3-hydroxybutyrate)

Microbial Cell Factories

卷:22

Research

Hirotaka Kudo¹  Shigeru Chohnan¹  Kenta Abe¹  Munehiko Asayama¹  Hirofumi Nishihara¹  Sho Ono¹  Tomoyasu Nishizawa¹  Mami Matsuda²  Tomohisa Hasunuma³ 

[1] Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, 300-0393, Ami, Ibaraki, Japan;

[2] Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, 657-8501, Nada, Kobe, Japan;

[3] Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, 657-8501, Nada, Kobe, Japan;Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, 657-8501, Nada, Kobe, Japan;

关键词: Coenzyme A;    Acetyl-CoA;    Pantothenate kinase;    Poly(3-hydroxybutyrate);    Escherichia coli;    Pantothenic acid;    β-Alanine;   

DOI  :  10.1186/s12934-023-02083-5

 received in 2023-01-24, accepted in 2023-04-06,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundCoenzyme A (CoA) is a carrier of acyl groups. This cofactor is synthesized from pantothenic acid in five steps. The phosphorylation of pantothenate is catalyzed by pantothenate kinase (CoaA), which is a key step in the CoA biosynthetic pathway. To determine whether the enhancement of the CoA biosynthetic pathway is effective for producing useful substances, the effect of elevated acetyl-CoA levels resulting from the introduction of the exogenous coaA gene on poly(3-hydroxybutyrate) [P(3HB)] synthesis was determined in Escherichia coli, which express the genes necessary for cyanobacterial polyhydroxyalkanoate synthesis (phaABEC).ResultsE. coli containing the coaA gene in addition to the pha genes accumulated more P(3HB) compared with the transformant containing the pha genes alone. P(3HB) production was enhanced by precursor addition, with P(3HB) content increasing from 18.4% (w/w) to 29.0% in the presence of 0.5 mM pantothenate and 16.3%–28.2% by adding 0.5 mM β-alanine. Strains expressing the exogenous coaA in the presence of precursors contained acetyl-CoA in excess of 1 nmol/mg of dry cell wt, which promoted the reaction toward P(3HB) formation. The amount of acetate exported into the medium was three times lower in the cells carrying exogenous coaA and pha genes than in the cells carrying pha genes alone. This was attributed to significantly enlarging the intracellular pool size of CoA, which is the recipient of acetic acid and is advantageous for microbial production of value-added materials.ConclusionsEnhancing the CoA biosynthetic pathway with exogenous CoaA was effective at increasing P(3HB) production. Supplementing the medium with pantothenate facilitated the accumulation of P(3HB). β-Alanine was able to replace the efficacy of adding pantothenate.

【 授权许可】

CC BY   
© The Author(s) 2023

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