DETOXIFICATION AS A STRATEGY FOR DEVELOPING TOLERANCE IN Saccharomyces cerevisiae TO PHENOLIC COMPOUNDS

Other conference contribution, 2014

Several phenolic compounds are formed as products of lignin breakdown during pretreatment of lignocellulosic biomass. These phenolic compounds are inhibitory to cell growth and function as biocatalysts in the production of second generation biofuels from degraded lignocellulosic biomass. Our research is focused on developing a Saccharomyces cerevisiae strain with improved resistance to phenolic compounds. As part of our study, we have focused on understanding the ability of S. cerevisiae to tolerate and convert phenolic compounds. We aim to understand the conversion mechanisms of phenolic compounds and adapt the knowledge to the engineering and use of S. cerevisiae on a biotechnological platform for bioethanol production and prospective, novel bio-based chemicals. We have investigated toxicity of various phenolic compounds against S. cerevisiae. Our results showed that phenolic compounds have varied toxicity against S. cerevisiae and the toxicity may be dependent on the structure of the compound involved. Under aerobic batch cultivation conditions, we have also studied the conversion of phenolic compounds by S. cerevisiae using coniferyl aldehyde, ferulic acid and p-coumaric acid as representative phenolic compounds. We compiled a list of conversion products of the three starting compounds under investigation and we proposed a possible conversion pathway, currently being investigated. In this talk, we present the proposed conversion pathway through which S. cerevisiae converts and detoxifies coniferyl aldehyde, ferulic acid and p-coumaric acid under aerobic cultivation condition.