Isolation And Identification Ofcorn Straw Degradationbacteria And Its Degradationproperties

The corn straw resources were abundant in China.Straw incorporation not only lightened the environmental pressure,but also realized the high value utilization of cellulosic biomass.It is of great practical significance to improve the efficiency of straw incorporation by microbe in order to solve the environmental pollution so far.In this study,two lignocellulosic fungi were isolated from the soil covered with straw all the year round.The lignocellulosic feedstocks degradation ability of two fungi was evaluated based on the Congo red staining and filter paper strips test.The result indicated that two fungi with high ability of corn straw degradation.The cellulase and ligninase test indicated that cellulase?CMC,FPA?,?-glucosidase??-glucosidase?and hydrogen peroxide?H₂O₂?could be expressed simultaneously.The result of static degradation experiment of corn straw by strain Z-3 showed that the weight loss ratio of corn straw reached 26.76%after 30 days which higher than other strains.The sequence analysis of 18S rDNA showed that the fungus Z-3belonged to Aspergillus fumigatus,which was designated as Aspergillus fumigatus CLL?A.fumigatus CLL?.To evaluate the corn straw degradation performance of A.fumigatus CLL,corn straw was used as substrate in static solid fermentation under 30 ^oC for 60 days.The results showed that the contents of total sugar and reducing sugar decreased significantly after 25 days.Meanwhile,the cellulose,hemicellulose and lignin reduced by 44.78%,33.86%and 52.22%,respectively.The result indicated that A.fumigatus CLL with a strong ability on corn straw degradation.What's more,lignin degradation performance was obviously than cellulose and hemicellulose.Structural changes of corn straw during degradation were discussed in this study.The functional groups of corn straw were analyzed by Fourier transform infrared spectroscopy?FTIR?.The results showed that the relative intensity of hydroxyl correlation(1372¹375 cm^-1)and phenol absorption(1515¹516cm^-1)peak were enhanced which indicated lignocellulose had been decomposed into an available short-chain structure.A.fumigatus CLL able to degrade corn straw effectively.