Fig. 2

Cellulase production of SS-II-cre1₉₆. a Schematic diagram of the construction of the mutant SS-II-cre1₉₆. The truncated form of the cre1₉₆ sequence from RUT-C30 was introduced in SS-II to replace the full-length cre1 by double crossover exchange. The hygromycin cassette was excised to form SS-II-cre1₉₆. T. reesei strains were cultivated in MA medium using lactose as the carbon source. FPase activity was calculated in two types of units, U/mL (b) and IU/mg biomass (c). pNPCase activity was also calculated in two types of units, U/mL (d) and IU/mg biomass (e). Values are the mean ± SD of the results from three independent experiments. Asterisks indicate significant differences (*p < 0.05, **p < 0.01, ***p < 0.001, Student’s t-test)