Studies On Cellulase Production And Enzymatic Hydrolysis Of Furfural Residues

Cellulase is composed of several different enzymes. The component and enzyme activity of cellulase which is isolated from the different fungi fermentation, because the substrate of enzyme-catalyzed reaction is complex. The aim of the experiment is to evaluate cellulase production from different fungi.This experiment picks up four kinds of fungi which produce cellulase, which are CGMCC3.2941、 CICC13007、CICC40360. and ACCC30557. These fungi were selected for cellulase production using furfural residues and microcrystalline cellulose (MCC) as the substrates. After cellulase production, the filter paper activity (FPA) of the supernatant from each fungus was measured to compare the performance of the enzyme from different fungal strains. Moreover, the individual activities of β-glucosidase, endoglucanase, and exoglucanase were also evaluated. In the case of CGMCC3.2941and CICC13007, furfural residues supported a better environment for cellulase production than MCC.The FPAs of CGMCC3.2941and CICC13007in furfural residues were6.31U/mL and0.64U/mL higher than that in MCC, respectively.Furfural residues with different cellulose contents were hydrolysed by a mixture of cellulase which are from CGMCC3.3002, CICC13007. CICC13052and Celluclast1.5L and β-glucosidase. The glucose yield of furfural residues increased incrementally according to the cellulose content of the substrate. The highest glucose yield (92.06%) in the digest with Celluclast1.5L preparation was obtained from the enzymatic hydrolysate of the furfural residue with a cellulose content of94.92%. The glucose yield in the digest with cellulase preparation from CGMCC3.3002is83.76%. After removing of ligin. the efficiency of degradation of cellulose increased, which indicated that there was non-productive adsorption between the enzyme and the lignin in the furfural residues. The increase of hydrolysis efficiency due to removing the impact of ligin on cellulase and thus the better adsorption and desorption between the cellulase and cellulose.Furfural residues were hydrolysed by a mixture of cellulase, which contain the cellulase from CGMCC3.2941, CGMCC3.3002and CICC1007. During the hydrolysis, β-glucosidase from ACCC30557was added into the digest. The result showed the highest glucose yield in the digest with the cellulase mixture of CGMCC3.2941and CGMCC3.3002is80%. There is synergistic action among the different constituents.In the experiment, after different UV exposure time, the death rate of the Neurospora crassa was determined. Compared to the initial Neurospora crassa, the cellulase production from Neurospora crassa after ultraviolet mutagenesis was improved by30%. After optimizing, Neurospora crassa after ultraviolet mutagenesis can be used drectly in the production of ethanol.