Improved polyhydroxybutyrate production by Saccharomyces cerevisiae through the use of the phosphoketolase pathway
Journal article, 2013

The metabolic pathways of the central carbon metabolism in Saccharomyces cerevisiae are well studied and consequently S. cerevisiae has been widely evaluated as a cell factory for many industrial biological products. In this study, we investigated the effect of engineering the supply of precursor, acetyl-CoA, and cofactor, NADPH, on the biosynthesis of the bacterial biopolymer polyhydroxybutyrate (PHB), in S. cerevisiae. Supply of acetyl-CoA was engineered by over-expression of genes from the ethanol degradation pathway or by heterologous expression of the phophoketolase pathway from Aspergillus nidulans. Both strategies improved the production of PHB. Integration of gapN encoding NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase from Streptococcus mutans into the genome enabled an increased supply of NADPH resulting in a decrease in glycerol production and increased production of PHB. The strategy that resulted in the highest PHB production after 100h was with a strain harboring the phosphoketolase pathway to supply acetyl-CoA without the need of increased NADPH production by gapN integration. The results from this study imply that during the exponential growth on glucose, the biosynthesis of PHB in S. cerevisiae is likely to be limited by the supply of NADPH whereas supply of acetyl-CoA as precursor plays a more important role in the improvement of PHB production during growth on ethanol.


phosphoketolase pathway




Kanokarn Kocharin

Chalmers, Chemical and Biological Engineering, Life Sciences

Verena Siewers

Chalmers, Chemical and Biological Engineering, Life Sciences

Jens B Nielsen

Chalmers, Chemical and Biological Engineering, Life Sciences

Biotechnology and Bioengineering

0006-3592 (ISSN) 1097-0290 (eISSN)

Vol. 110 8 2216-2224

Industrial Systems Biology of Yeast and A. oryzae (INSYSBIO)

European Commission (EC) (EC/FP7/247013), 2010-01-01 -- 2014-12-31.

Subject Categories

Industrial Biotechnology

Areas of Advance

Life Science Engineering (2010-2018)



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