Fig. 9From: A novel sucrose-inducible expression system and its application for production of biomass-degrading enzymes in Aspergillus nigerExpression properties of chitinolytic enzymes in A. niger FCN30. RT-qPCR analysis of the expression levels of chi46 (A) and nag1 (B) in FCN30. Actin was used as a reference gene and the 2−ΔΔCt method was used for calculating relative expression levels. C SDS-PAGE analysis of the extracellular protein of FCN30 and the parental strain ATCC 20611 (20611) on sucrose. D Determination of the chitinase activities of strains using colloidal chitin as the substrate. E Determination of the GlcNAcase activities of strains using pNP-NAG as the substrate. F Quantification of extracellular protein concentrations of FCN30 and the parental strain ATCC 20611 (20611) by the Bradford method. Values and standard deviation (SD) of triplicates are presented in the figure. Asterisks indicate statistically significant differences (**p < 0.01) as assessed by Student’s t test. n.d., not detectedBack to article page