FIGURE 1.

Mannitol production and phylogenetic analyses of mannitol-related genes in W/S-clade species. (A) Mannitol yields determined after 72–150 h of growth on YP medium supplemented with 10% (w/v) glucose or 10% (w/v) fructose at 30°C in several W/S-clade species (Starmerella bombicola, Candida magnoliae, Starmerella bacillaris, Wickerhamiella domercqiae and Wickerhamiella versatilis). Assays were performed in duplicate and the error bars represent the standard deviation. (B) Mannitol biosynthetic pathways in Fungi as described by Hult et al. (1980). Glk – Glucokinase, Hxk – Hexokinase, Pgi – Phosphoglucose isomerase, Mtdh – mannitol dehydrogenase, Mpp – mannitol-1-phosphate phosphatase, M1pdh – mannitol-1-phosphate dehydrogenase. (C) Pruned Maximum Likelihood (ML) phylogeny of Mtdh-like proteins using the top 750 hits (UniprotKB database) to St. bombicola Mtdh1. Branches with support higher than 95% are indicated by black dots. W/S-clade proteins are shown in red. Complete phylogeny can be accessed in Figshare 10.6084/m9.figshare.9959693. (D) Schematic representation of the phylogenetic relationships between W/S-clade species based on Gonçalves et al. (2018). MtDH genes are represented by blue circles (dark blue- MtDH1, light blue- MtDH2). The duplication events are represented by white boxes in the respective branches in which they were assumed to have occurred. In W. versatilis, MtDH1 seems to have been lost (faded dark blue circle).