Strategies and genetic tools for engineering free-energy conservation in yeast

Abstract

Microbial production of fuels and chemicals provides opportunities for replacing conventional production processes, which are based on chemical synthesis from non-renewable raw materials or on labour- and capital-intensive extraction from animal or plant tissues. Aeons of evolution, in which astronomical numbers of microorganisms competed for scarce resources, have optimized and streamlined the thousands of biochemical conversions in their cells for growth in specific natural environments. The resulting metabolic diversity, represented by many millions of microbial species, offers a great potential for developing novel microbial conversions of renewable substrates to products. Major advances in (recombinant) DNA technology have enabled the engineering of several microorganisms into efficient production platforms, which can be further modified for the production of a wide range of fuels and chemicals. For high-volume products based on microbial fermentation, such as transport fuels and commodity chemicals, the use of substrate can comprise up to 70% of the total product costs. These high substrate costs make a high product yield on the substrate essential for economic viability.