Investigating Cellulases Charactors Of Newly Isolated Neurosporacrassa CGMCC3088Using Agricultural Wastes In Solid-state Ferementation

This article utilized bean dreg as medium substrate inoculating Neurosporacrassa CGMCC3088to extract cellulase from72h solid state fermentation substrates.The result showed extract time, pH value of buffer and the volume of buffer were themain factors through single factor experiment and Plackett-Burman design. Theoptimized extraction condition was acquired through Response Surface Methodology,which was solid substrate with sodium acetate buffer (0.1M, pH5.2;1:10w/v)shaked for30min. Under this method, the FPA activity can be acquired1.702IU/mL.We took advantage of beer lee, oil-tea seed cake, rice straw, bean dreg and beanhull as sole carbon source on solid state fermentation. Comparison of the peak time ofcellulase production, enzymatic system and characters of cellulase activity amongthem were done using Neurospora crassa CGMCC3088. The highest activities ofFPase (2.242U/g), Endoglucanases (9.084U/g), Exoglucanases (7.156U/g) andβ-Glucosidases (1.85U/g) were obtained in beer lee with48h cultivation, bean hullwith60h and72h cultivation, bean dreg with60h cultivation, respectively. Content ofnutrients in substrate were positively related to the best time of cellulase production.The complemantary experiments of bean hull and rice straw, added certain glucoseand peptone, showed the high level of nutrients culture medium advanced the peakcellulase production and rised the enzyme activities. The activities of C1and Cx inthis test group were increased41.76%、60.38%and68.06%、60.1%respectively. Theresults indicated that Neurospora crassa growed better on the substrates whichcontented more cellulose but less lignin. Above all, the degrade efficiency of cellulosewas better than hemicellulose and lignin in all test group.The crystallinity and the surface structure of the untreated and fermentedagricultural residues were inspected by X-diffraction and scanning tunnelingmicroscopy. It indicated that the crystallinity of cellulose in beer lee, rice straw,oil-tea seed, bean dreg and bean hull was47.5、75、53.13、43.2and61.2(Segalmethod). Nevertheless, Oil-tea seed and bean hull showed the most severe decreaseon crystallinity for their strong degrade ability of cellulases. The diffraction peak areawas smoother and microscopic pictures showed bonds between fasciculus were demaged and shape of fiber was changed to pieces.The study also deliberately selected Issatchenkia oriental, Trichodermareesei,Trichoderma vivide and L.plantarum to combine Neurospora crassa CGMCC3088respectively, in order to find the potential microorganisms which can promote thecellulase production. The enzyme activity of C1from Neurospora crassa&Trichoderma vivide had increased51.09%compared with single fermentation ofNeurospora crassa, meanwhile, it postponed the secretion period of cellulases, theenzyme activity of FPA reached2.782U/g after96h. Neurospora crassa mixedfermentation with Trichodermareesei, Trichoderma vivide, which led to a greatdescent of crude fiber that the degrade rate accounted to64.19%,61.59%respectively.when it came to L.plantarum and Issatchenkia oriental, the ultimate degrade rate ofcrude fiber was just34.92%and41.89%With the augment of inoculum, the overalltendency of enzyme activity was ascented. The research showed Neurospora crassawas able to cooperate with Trichodermareesei, Trichoderma vivide individually todegrade cellulose rather with Issatchenkia oriental and L.plantarum.