화학공학소재연구정보센터
Journal of Bioscience and Bioengineering, Vol.126, No.3, 317-321, 2018
Expression of Saccharomyces cerevisiae cDNAs to enhance the growth of non-ethanol -producing S. cerevisiae strains lacking pyruvate decarboxylases
Metabolic engineering of Saccharomyces cerevisiae often requires a restriction on the ethanol biosynthesis pathway. The non-ethanol-producing strains, however, are slow growers. In this study, a cDNA library constructed from S. cerevisiae was used to improve the slow growth of non-ethanol-producing S. cerevisiae strains lacking all pyruvate decarboxylase enzymes (Pdc(-), YSM021). Among the obtained 120 constructs expressing cDNAs, 34 transformants showed a stable phenotype with quicker growth. Sequence analysis showed that the open reading frames of PDC1, DUG1 (Cys-Gly metallo-di-peptidase in the glutathione degradation pathway), and TEF1 (translational elongation factor EF-1 alpha) genes were inserted into the plasmids of 32, 1, and 1 engineered strains, respectively. DUG1 function was confirmed by the construction of YSM021 pGK416-DUG1 strain because the specific growth rate of YSM021 pGK416-DUG1 (0.032 +/- 0.0005 h(-1)) was significantly higher than that of the control strains (0.029 +/- 0.0008 h(-1)). This suggested that cysteine supplied from glutathione was probably used for cell growth and for construction of Fe-S clusters. The results showed that the overexpression of cDNAs is a promising approach to engineer S. cerevisiae metabolism. (C) 2018, The Society for Biotechnology, Japan. All rights reserved.