Figure 7. Maf1-deficient yeast strain accumulates glycogen (A) and trehalose (B) during the exponential phase.

Yeasts were cultivated in rich medium supplemented with 2% glucose and harvested by centrifugation at D₆₀₀ ≈ 1.0. Glucose concentration from enzymatic breakdown of glycogen (A) by amyloglucosidase from A. niger, was determined by the Glucose (HK) Assay Kit (GAHK-20, Sigma). Trehalose (B) content determination assay was performed using Trehalose Assay Kit (Megazyme International Ireland, Wicklow, Ireland) according to the manufacturer's protocol. Trehalose and glycogen content is presented as a mean value of at least three independent biological replicates with standard deviations. There were no significant changes in the ethanol production rate between wild-type (MB159-4D) and maf1Δ strain (C). maf1Δ accumulated glycerol (D). Ethanol and glycerol concentration was determined under Fermentative capacity assay (FCA) conditions in maf1Δ strain (C and D). Fermentative capacity assay was performed as described by van Hoek et al. [75] with modifications (for details, see Materials and methods section). All assays were performed in triplicates. Results are shown as mean concentration (g/L) value with the standard deviation in time (min). ‘C-limited’ stands for ‘carbon-limited conditions’. Asterisk (*) indicate P-value <0.05 and double asterisk (**) illustrate P-values <0.1 according to Student's t-test calculated from biological replicates.