Screening Of Strains With High Cellulase Activity

Cellulase is used widely in food, wine, feed-processing and other fields. The strain so easy degeneration and low production that caused high costs of the cellulase and small scale operation. Improve the yield of cellulase in order to make it better used in industry, it is significance to breeding high cellulase producing strains.35 strains'fungi producing cellulase which grew well and transparent circles clear, were isolated by Congo-red dyeing from decaying straw, chaff and leaves.16 strains of high FPAase and CMCase'fungi were rescreened from 35 strains by the method of DNS and disintegration of filter papers. And then through solid fermentation obtained 6 strains which have stable and efficient CMCase and FPAase activity. Strain H has highest cellulase-production, the activity of CMC and FPA are 2993.3 U/g and 346.56 U/g.Three methods were used for extracting strain H's DNA, Universal fungal primer ITS1 and PITS4 was used to amplify ITS sequence's rDNA by PCR. Strain H may be a new specie identified by the Blasted ITS sequences in NCBI DNA database and the morphological characteristics of spores and hyphae.Strains H was mutated by UV mutagenesis, found out that mutated 160s get the best result, and get a mutated strain H1. CMC's activity of HI is 3554.88 U/g and FPA's activity is 506.76 U/g. CMC's activity and FPA's activity of strain HI are 1.18 times and 2.48 times more than the original strain, the enzyme activity of H1 is stability after Subculture H1.