UV mutagenesis of Aspergillus niger for increasing pectinase production and its solid-state fermentation using grape skin residue

For increasing pectinase productiont, UV light was used to produce Aspergillus niger mutagenesis, and the grape skin residue was used to produce pectinase by Aspergillus niger. The results showed that, in the eight Aspergillus niger strains H40741, H40493, H40982, H41133, H41134, H41034, H40493 and H22148, the H40741 has the highest pectinase activity.Ultraviolet light on H40741 spores 0³60 s, and we obtained a high yield pectinase mutant strain H40741-20. The pectinase activity was 462.84 U/m L in pectin liquid fermentation medium, which was 3 times of the original strain. By optimizing the contents of grape skin residue, wheat bran and water, we obtained a better medium formula was grape skin residue 50 g, wheat bran 50 g, water 100 m L, ammonium sulfate 2 g, magnesium sulfate 0.07 g, potassium sulfate.The pectinase enzyme activity was421.06 U/m L, which was 2.7 times higher than that of the original strain H40741 by using this optimized solid medium.