Fig. 4
Polycarbohydrate metabolism in D. papillatum. A Proteins containing at least one CAZyme domain. Proteins were grouped by their cognate substrate class. The subdivision of the bars by different color shades represents the number of enzymes in the following subgroups. pectin: pectin hydrolases, pectin lyases, pectin acetylesterases, and pectin methylesterases. cellulose & related: cellulases, xylan-α-glucuronidases, xylan/cellulose and xylan/xyloglucan hydrolases, hemicellulases, β-glucan/β-xylan hydrolases, and β-mannanases. β-1,3-glucan: no subgroups. glucuronomannan: α-mannanases and β-glucuronidases. chitin & related: chitinases, glycosaminoglycan and glucosamine hydrolases. N-glycan: no subgroups. oligomers and others: α-glycosidases, β-glycosidases, trehalases, an α-fucanase, and an invertase. B Distribution of the CAZyme families GH (glycoside hydrolase), PL (polysaccharide lyase), CE (carbohydrate esterase), and CBM (carbohydrate-binding module) across four free-living euglenozoans (D. papillatum, D. japonicum, B. saltans, and E. gracilis) and two representative fungi (Trichoderma reesei and Phanerochaete chrysosporium). Rows correspond to individual CAZyme families with heatmap shading indicating the number of family members in each genome as detailed in the key (bottom). C DIPPA_15749, a GH115-family member and its 12 paralogs, were most likely acquired specifically by D. papillatum via horizontal transfer from diverse bacteria. Sequences that belong to bacteria, fungi, and diplonemids other than D. papillatum are highlighted in shades of yellow, beige, and light blue, respectively. For details, see Additional file 1: Sect. 15. Genes horizontally transferred from bacteria to Diplonema papillatum. D Biomass of D. papillatum cells grown in various substrates. The cell sizes are represented as circles of different diameter and the predominance of the various sizes by the grey shade of the fill. Cells were counted in triplicate after six days and weighed to calculate their biomass (wet weight per 108 cells). Bars indicate the mean deviation of the cell counts for each of the four independent biological replicates. Note that the predominant cell size correlates with both biomass and the number of granules