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Improvement of d ‐lactic acid productivity by introducing Escherichia coli acetyl‐CoA synthesis pathway in engineered Saccharomyces cerevisiae
Author(s) -
Zhong Wei,
Yang Maohua,
Hao Xuemi,
Sharshar Moustafa M,
Wang Qinhong,
Xing Jianmin
Publication year - 2021
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6787
Subject(s) - biochemistry , alcohol dehydrogenase , acetaldehyde , escherichia coli , metabolic engineering , chemistry , fermentation , lactic acid , pyruvate dehydrogenase complex , dehydrogenase , saccharomyces cerevisiae , lactate dehydrogenase , glycerol , yeast , enzyme , biology , bacteria , ethanol , gene , genetics
BACKGROUND d ‐Lactic acid ( d ‐LA) is gaining increased attention as it can be applied in the food, pharmaceutical, cosmetic, polylactic acid and textile industries. Acid‐tolerant Saccharomyces cerevisiae is often engineered to produce organic acids. For the pyruvate decarboxylases (PDCs) or alcohol dehydrogenase 1 (ADH1) disrupted strains, the productivity of d ‐LA significantly decreases due to the accumulation of acetaldehyde and acetic acid. To overcome the problem, Escherichia coli acetylating acetaldehyde dehydrogenase (A‐ALD) enzyme genes ( MHPF and EUTE ) (EC 1.2.1.10) were integrated into the d ‐LA producing strain YIP‐A15G12 strain (CGMCC2.5803). The function of these genes is to directly convert acetaldehyde into acetyl‐CoA without energy consumption. This strain was integrated with Escherichia coli d ‐lactate dehydrogenase and Issatchenkia orientalis glycosylphosphatidylinositol‐anchored protein IoGas1gene and several attenuated key pathway genes, including PDC1 , PDC6 , ADH1 , ADH5 , JEN1 (a monocarboxylate transporter), d ‐lactate dehydrogenase 1 ( DLD1 ), l ‐lactate cytochrome c oxidoreductase ( CYB2 ) and glycerol‐3‐phosphate dehydrogenases ( GPD1 , GPD2 ). RESULTS The strain expressions of the A‐ALD enzymes effectively complemented the attenuated acetaldehyde dehydrogenase (ALD) acetyl‐CoA synthetase (ACS) pathway and significantly improved the levels of acetyl‐CoA and the productivity of d ‐LA. Finally, the resulting strainYIP‐m‐ald6 (CGMCC2.5826) produced 86.9 g L –1 d ‐LA with a yield of 0.77 g g –1 glucose and a volumetric productivity of 1.77 g L –1 h –1 at pH 3.58 under fed‐batch fermentation conditions. CONCLUSION Introducing the E. coli acetyl‐CoA synthesis pathway into the yeast strain can significantly enhance the growth of the strain and improve the d ‐LA productivity, as a benefit for d ‐LA production in industry. © 2021 Society of Chemical Industry (SCI).