Diversity Of Cellulase-producing Low-temperature Fungi And Their Functions In The Cangshan Mountain

Cellulase-producing low-temperature fungi play an important ecological role in carbon metabolism at high altitudes and low temperatures,but systematic studies of their diversity and functions are still lacking.In this work,the diversity of cellulase-producing low-temperature fungal strains in the Cang Shan region was analysed,and functional studies were conducted on the strains that degrade lignocellulose and produce cellulosic ethanol.1.A total of 117 low temperature fungal strains have been obtained from the Cangshan area and have been identified to belong to 21 genera,of which Cladosporium,Candida,Mucor,Penicillium were the dominant genera;15 strains of the genera Candida,Mortierella,Penicillium were cold-loving strains of Aspergillus,Amesia,Bjerkandera,Beauveria,Cladosporium,Chaetomium,Coprinellus,Chaetomium,Dothideomycete,Gliomastix,Leucosporidium,Pleosporales,Prosthecium,Phanerochaete,Pseudogymnoascus,Peniophora,Penicillium,Saccharomycetales,Trichosporon,Trichoderma,Tolypocladium,The102 strains of the genus Neonectria are cold tolerant.The Shannon-Wiener indices at 2091 m,2400m,2827 m and 3306 m were 0.85,2.36,1.54 and 1.39 respectively.Diversity is higher at 2400 m than at other altitudes.2.Three strains of Candida sp.with lignin degrading ability,DLME010113,DLME010115 and DLME010241,were screened and their enzymatic sugar yield increased by 2.3,2.37 and 2.45 times respectively after treatment with lignocellulose;their fermentation broth increased by 1.47,1.15 and 1.86 times respectively after treatment with lignocellulose.The lignocellulosic fermentation broth increased enzymatic sugar production by 1.47,1.15 and 1.86 times respectively.This indicates that the three strains can have a certain degrading effect on crop straw,which has important development and utilization value in the resource utilisation of agricultural straw.3.Screening yielded the Candida genera strains DLME010211 and DLME010235 with cellulosic ethanol production capacities of 14.15±0.40 mg/L and 17.84±0.21 mg/L,respectively.Using transcriptome sequencing technology and bioinformatics analysis,five new cellulase genes were predicted from the two yeast strains,providing data to further investigate the molecular mechanism of cellulose ethanol production by low-temperature fungi.This study is important for understanding the diversity of low-temperature fungi in the Cang Shan region,enriching the low-temperature fungal resource base,managing environmental pollution and alleviating the energy crisis.