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BMC Proceedings

Open Access

Increasing ATP conservation in maltose consuming yeast, a challenge for industrial organic acid production in non-aerated reactors

  • Stefan de Kok1,
  • Wesley Leoricy Marques2,
  • Robert Mans1,
  • Duygu Yilmaz1,
  • Erwin Suir1,
  • Jack T Pronk1,
  • Andreas K Gombert2, 3,
  • Jean-Marc Daran1 and
  • Antonius JA van Maris1
BMC Proceedings20148(Suppl 4):P185

https://doi.org/10.1186/1753-6561-8-S4-P185

Published: 1 October 2014

Anaerobic fermentation processes are economically attractive for industry, as costs for aeration and stirring are greatly reduced. An example of such a process is (bio)ethanol production by Saccharomyces cerevisiae, in which a low but positive ATP gain leads to elevated product yields. However, for other fermentative pathways, such as in an engineered homolactic strain of S. cerevisiae, the net ATP gain for the fermentation of glucose to lactate is null due to the requirement of ATP for product export. Therefore, increasing the conservation of ATP is of major importance for such 'zero-ATP pathways'.

One opportunity to increase ATP conservation arises when disaccharides are used as a substrate. In many industrial microorganisms, disaccharides are cleaved by hydrolysis, which results in the dissipation of energy that is available in this cleaving reaction. However, phosphorolytic cleavage could be used to replace the hydrolysis of disaccharides, thereby increasing the ATP yield.

In this study, growth of S. cerevisiae on maltose was used as a model. All known native maltose metabolism genes were removed and replaced by a maltose phosphorylase (Lactobacillus sanfranciscensis) and a single overexpressed copy of the native MAL11 maltose transporter. Because maltose phosphorylase cleaves maltose into glucose and β-glucose-1-phosphate, additionally a β-phosphoglucomutase (Lactococcus lactis) was co-expressed in this strain.

Anaerobic maltose-limited chemostat cultures showed that replacement of maltose hydrolysis by phosphorolysis increased the biomass yield of the mutant strain by 26% over the wild type strain, demonstrating the potential of phosphorolysis to improve ATP conservation of disaccharide metabolism in industrial microorganisms [1].

Authors’ Affiliations

(1)
Department of Biotechnology, Delft University of Technology and Kluyver Centre for Genomics of Industrial Fermentation
(2)
Department of Chemical Engineering, University of São Paulo
(3)
Faculty of Food Engineering, University of Campinas

References

  1. De Kok S, Yilmaz D, Suir E, Pronk JT, Daran JM, van Maris AJA: Metab Eng. 2011, 5: 518-526.View ArticleGoogle Scholar

Copyright

© Kok et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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