Research On The Screening Cellulase-producing Fumigatus Strain And The Conditions Of Cellulase Producing

Research on the separation and screening of cellulase-producing thermotolerant fungi strains, a preliminary study on enzyme production characteristics and using of the advantage of strains to treatment of the straw and cassava vinasse.A thermotolerant cellulase-producing fungal strain E4was isolated from the soil. Experimental results show that it can grow under of20℃the optimum growth temperature is40℃, and the supreme growth temperature is55℃. Its best enzyme production conditions is straw as fermentation mediums. E4was identified as Aspergillus fumigatus by morphological characteristics as well as by the18S rRNA gene sequence. The optimal enzyme production pH is5.0, and the temperature is42℃the maximum CMCase (hydroxyl methyl cellulose enzyme) activity is3.5u/mL, maximum FPA filter paper enzyme) activity is3.2u/mL after72hours at the temperature of45℃liquor fermentation. The strain could effectively degradate the straw and the degradation rate of staw is63.5%in7days.A thermotolerant cellulase-producing fungal strain XT3was isolated from the soil. XT3was identified as Aspergillus fumigatus by morphological characteristics as well as by the18S rDNA gene sequence. The optimal enzyme production pH is4.0, and the temperature is45℃In vinasse culture medium,4%in cassava straw culture medium,4%bran medium fermentation, the maximum CMCase (hydroxyl methyl cellulose enzyme) activity is3.5u/mL, maximum FPA (filter paper enzyme) activity is1.97u/mL and2.04u/mL in vinasse culture, FPA filter paper enzyme) activity in vinasse culture is2.2times in the straws. It has great influence on cellulase-producing in cassava vinasse adding different active ingredients, Its enzymatic activity is by2.1times than not add any component of vinasse. The fungus is concerned that high temperature fungi may produce good resistance high temperature decomposition of cellulose enzyme, through XT3resistant temperature experiments of the production of cellulose enzyme, it is that the cellulose enzyme resistant temperature is better than aspergillus, that XT3maximum enzyme activity is3.2u/mL in80℃, that aspergillus maximum enzyme activity is1.68u/mL in60℃. It is best to obtain enzyme for XT3in cassava vinasse fermention in salting-out60%degrees, the enzyme through the spin after evaporation and concentration eight times in50℃is five times than not concentrated before. XT3strain has potential for cassava vinasse applications and research value, and it can further research.