PhD defence

Harnessing additional metabolic energy during fermentation processes: will the proton-motive force be with you?


Microbial production of low-cost chemicals such as biofuels and bulk chemicals requires high titer, rate and especially yield to be able to compete with petrochemical-based processes. To achieve high yield, the metabolic pathways involved in product formation should be redox-balanced and conserve sufficient metabolic energy to fulfil the cells’ requirements for maintenance and growth. Thanks to advances in omics and genetic engineering tools, redox-balanced product pathways can be created, however, product yield is – in most cases – limited by energy conservation. Capturing additional energy can lead to higher product titer or allow microorganisms to grow under inhibitory conditions (high cell density cultivation and high product titer) depending on the product of interest. In this thesis, we designed a generally applicable strategy to capture additional metabolic energy from sugars in E. coli. We also proposed alternative methods to further increase microbial product formation.