Screening,identification of a high-yield cellulase producing Aspergillus niger strain and optimization of its enzyme production conditions
ZHANG Ting
LÜ Qingyang
YAN Zhiying
WANG Xinhui
Abstract：This experiment aimed to screen a strain with high cellulose degradation ability and good safety,and optimize its fermentation process.Strains were screened based on the diameter of cellulose hydrolysis zones,filter paper enzyme(FPase)activity,and carboxymethyl cellulase(CMCase)activity.Solid-state fermentation for cellulase production was conducted using corn straw as the main substrate,and the enzyme production conditions were optimized through single-factor and orthogonal experiments.The results showed that after molecular identification,the candidate strain H8 was Aspergillus niger.Under fermentation at 30 ℃,the FPase activity of Aspergillus nigerH8 peaked on the 5th day(15.20 U/g),while CMCase activity peaked on the 6th day(15.90 U/g).The optimal solid-state fermentation conditions for cellulase production were determined as follows:Corn straw to wheat bran ratio of 4:1,ammonium sulfate addition of 0.25％,inoculum size of 4％,moisture content of 67％,initial pH value of 8,and fermentation at 31 ℃ for 3 days.Under these conditions,the FPase and CMCase activities produced by Aspergillus niger H8 reached 35.78 U/g and 50.99 U/g,which were 135.39％and 220.69％higher than those under the initial fermentation conditions.The study shows that the strain of Aspergillus niger H8 isolated from soil has high cellulase activity and has a degrading effect on corn straw.
Keywords：Aspergillus nigersolid-state fermentationcellulase
Publication Date：2026-01-16
Online Publishing Date：2026-03-16(First online date of this platform, not the publication date of the document)
Pages：7( 111-117 )