Recombinant saccharomyces cerevisiae strains converting phenolic compounds

Inhibitory phenolic monomers are generated during biomass pretreatment steps as a result of lignin depolymerisation. There is a growing interest in understanding and harnessing the capacity of industrial microorganisms to convert these compounds. Such interest stems from at least two reasons: i) conversion could results in less-inhibitory products, hence representing an effective detoxification of the fermentation medium by the microorganism of choice; ii) conversion of the diverse mixture of lignin monomers could converge towards products of higher interest and added value as aromatic chemical intermediates.

Our research is focused on understanding the conversion pathways naturally present in Saccharomyces cerevisiae and on developing S. cerevisiae strains with the capacity of converting phenolic compounds to less-toxic compounds of interest.

We studied the conversion of phenolic compounds by S. cerevisiae under aerobic batch cultivation conditions. We compiled a list of conversion products and proposed a possible conversion pathway. Based on the hypothesized pathway, we generated a set of recombinant strains and evaluated their capacity to tolerate and convert coniferyl aldehyde as model compound, mapping the palette of conversion products in aerobic batch cultivations and demonstrating improved conversion capacity as a result of our strain engineering strategy.