Production of pyruvate from mannitol by mannitol-assimilating pyruvate decarboxylase-negative Saccharomyces cerevisiae

Abstract

Mannitol is contained in brown macroalgae up to 33% (w/w, dry weight), and thus is a promising carbon source for white biotechnology. However, Saccharomyces cerevisiae, a key cell factory, is generally regarded to be unable to assimilate mannitol for growth. We have recently succeeded in producing S. cerevisiae that can assimilate mannitol through spontaneous mutations of Tup1-Cyc8, each of which constitutes a general corepressor complex. In this study, we demonstrate production of pyruvate from mannitol using this mannitol-assimilating S. cerevisiae through deletions of all 3 pyruvate decarboxylase genes. The resultant mannitol-assimilating pyruvate decarboxylase-negative strain produced 0.86 g/L pyruvate without use of acetate after cultivation for 4 days, with an overall yield of 0.77 g of pyruvate per g of mannitol (the theoretical yield was 79%). Although acetate was not needed for growth of this strain in mannitol-containing medium, addition of acetate had a significant beneficial effect on production of pyruvate. This is the first report of production of a valuable compound (other than ethanol) from mannitol using S. cerevisiae, and is an initial platform from which the productivity of pyruvate from mannitol can be improved.

Pyruvate Production from Whey Powder by Metabolic Engineered Klebsiella oxytoca

“…For example, the mixture of glucose and xylose, crude glycerol, lignin, and mannitol have been used in the fermentative production of pyruvate (Table ). ,,,, In this study, K. oxytoca PDL-0 was engineered to produce pyruvate from whey powder.…”

“…For example, the mixture of glucose and xylose, crude glycerol, lignin, and mannitol have been used in the fermentative production of pyruvate (Table 3). 8,14,17,35,36 In this K. oxytoca PDL-0 was engineered to produce pyruvate from whey powder. Compared with other strains used for pyruvate production from regenerative resources, the engineered K. oxytoca PDL-YC strain offers advantages such as the high pyruvate concentration (62.3 g/L) and productivity (1.60 g/[L•h]).…”