N. crassa growth on aldonic acids. a Biomass accumulation of N. crassa provided with different carbon sources after 48 h. All samples were started with an equal inoculum of 1 × 106 cells/mL. The plate was imaged on a black background to highlight fungal growth. b Relative abundance of aldonic acids in the supernatants of cells provided with cellobionic acid at the time of inoculation (top) and 40 h (bottom). G1 glucose, G2 cellobiose, A1 gluconic acid, A2 cellobionic acid, A3 cellotrionic acid, NC no carbon control.