Plasma membrane as a crucial player in acetic acid effect on yeast
Conference contribution, 2017

Weak organic acids such as formic, acetic or lactic acid are known inhibitors of microbial growth and fermentation. Acetic acid toxicity to yeast cells has been explained by different theories, involving specific signaling effects triggering an active cell death program, reduction of intracellular pH and acetate anion accumulation. Regardless of the fact whether the actual effect of acetate involves one of these mechanisms or a combination thereof, acetic acid inhibits yeast metabolism and affects yeast viability. This has a high impact on the feasibility of the new generation of fermentation processes, based on the naturally acetic acid-rich lignocellulosic substrates. It is therefore highly desirable to obtain a strain with increased capacity of coping with high acetic acid concentrations in the fermentation medium. Acetic acid is thought to be internalized by yeast cells in its undissociated form, by crossing the hydrophobic barrier of plasma membrane. Thus, in our work we focused on the investigation of membrane properties and how these influence the tolerance of yeast to acetic acid. First, we demonstrated with lipidomics analysis of membrane lipids that the yeast Zygosaccharomyces bailii, showing extraordinary tolerance to acetic acid, has a plasma membrane which is rich in sphingolipids. Next, we combined membrane molecular dynamics and in vivo measurements to confirm the specific role of sphingolipids in altering the permeability of plasma membrane to acetic acid. Finally, we investigated the effect of alcohols on the acetic acid permeation rate through the membrane. Our ultimate goal is to engineer the membrane composition of an industrial yeast strain towards reduced permeability, in order to obtain higher acetic acid tolerance.

Author

Maurizio Bettiga

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Lina Lindahl

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Samuel Genheden

University of Gothenburg

Leif A Eriksson

University of Gothenburg

Lisbeth Olsson

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

IMYA12- 12th International Meeting on Yeast Apoptosis, Bari, Italy • 14-18 May 2017

Driving Forces

Sustainable development

Subject Categories

Industrial Biotechnology

Biochemistry and Molecular Biology

Biological Sciences

Microbiology

Areas of Advance

Energy

Life Science Engineering (2010-2018)

Roots

Basic sciences

More information

Created

1/24/2018