Fundamental studies reveal membrane engineering as strain engineering target for enhanced robustness towards lignocellulose hydrolysate inhibitors

Bio-processes for the production of fuels and chemicals will contribute to the so-called bioeconomy, where biomass will represent an important source of hydrocarbons. A new concept of bio-based industry is now under development, where lignocellulosic material is the primary source of sugars to be converted in a biorefinery concept not to ethanol or fuels only, but to a portfolio of chemicals. Regardless of the product, robust microorganisms are a prerequisite for the feasibility of lignocellulose bioconversion.

Current research carried out by our group focuses on the yeast Saccharomyces cerevisiae and aims at investigating the molecular bases of microbial robustness. The goal is to identify successful strain engineering strategies to confer yeast higher robustness.

Zygosaccharomyces bailii is a yeast specie that tolerates low pH and high concentrations of weak organic acids. Thus, in order to elucidate a possible link between lipid composition and acetic acid tolerance, a comparative lipidomic profiling of the major lipid species found in the plasma membrane of S. cerevisiae and Z. bailii was performed. The study revealed remarkable changes in glycerolphospholipids and sphingolipids pools in Z. bailii compared to S. cerevisiae, suggesting lipid saturation, high sphingolipid levels as possible determinants of acetic acid tolerance.