Fig. 1.

Mechanisms of different inhibitors commonly found in a hydrolysate. Weak acids (e.g. acetic and formic acid) diffuse into the cell and release protons. To maintain a neutral pH, cells transport the protons out under the consumption of ATP. HMF and Furfural inhibit glycolysis which leads to a slower growth rate. Furfural and aromatic compounds damage both the cell and plasma membranes. Formic acid and aromatic compounds cause the formation of reactive oxygen species (ROS). Adapted from [12]