Open AccessEvaluation of pyruvate decarboxylase‐negative Saccharomyces cerevisiae strains for the production of succinic acid
Author(s) -
Zahoor Ahmed,
Küttner Felix T. F.,
Blank Lars M.,
Ebert Birgitta E.
Publication year - 2019
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201900080
Subject(s) - pyruvate decarboxylase , pyruvate carboxylase , citric acid cycle , metabolic engineering , biochemistry , cofactor , pyruvate decarboxylation , saccharomyces cerevisiae , tricarboxylic acid , succinic acid , metabolic pathway , biology , acetyl coa , carboxy lyases , chemistry , enzyme , yeast , alcohol dehydrogenase
Dicarboxylic acids are important bio‐based building blocks, and Saccharomyces cerevisiae is postulated to be an advantageous host for their fermentative production. Here, we engineered a pyruvate decarboxylase‐negative S. cerevisiae strain for succinic acid production to exploit its promising properties, that is, lack of ethanol production and accumulation of the precursor pyruvate. The metabolic engineering steps included genomic integration of a biosynthesis pathway based on the reductive branch of the tricarboxylic acid cycle and a dicarboxylic acid transporter. Further modifications were the combined deletion of GPD1 and FUM1 and multi‐copy integration of the native PYC2 gene, encoding a pyruvate carboxylase required to drain pyruvate into the synthesis pathway. The effect of increased redox cofactor supply was tested by modulating oxygen limitation and supplementing formate. The physiologic analysis of the differently engineered strains focused on elucidating metabolic bottlenecks. The data not only highlight the importance of a balanced activity of pathway enzymes and selective export systems but also shows the importance to find an optimal trade‐off between redox cofactor supply and energy availability in the form of ATP.