Lignocellulosic biomass is an abundant renewable resource from plants and it has high potential to produce biofuel and bio sourced chemicals. lignocellulosic biomass composed of lignin, cellulose and hemicellulose by enzymatic hydrolysis these components converted into biofuel and bio sourced chemicals and materials. lignocellulose degraded synergistically by lpmos, xylanase and cellulase but due to structural complexity of biomass enzymatic depolymerisation is not so efficient. these enzymes are produced by broad range of microorganism including fungi, bacteria and actinomycetes, out of these fungi present large array of cellulose degrading enzyme. in recent mesophilic fungi are used in industry but thermophilic host have attracted extensive attention due to their good stability and low cost in production and efficiently degrade crystalline cellulose. chaetomium thermophilum (thermochaetoides thermophila) is a thermophilic fungus of the phylum ascomycota, living in temperatures up to 60 °c and efficiently degrade crystalline cellulose. based on secretome studies, c. thermophilum produces at least 51 enzymes, of which 23 are hydrolases and 28 are oxidases. the hydrolases are composed of 5 cbhs, 10 egs and 8 bgs, and the oxidative enzymes included 2 cdhs, 8 glucose–methanol–choline oxidoreductases (gmc oxidoreductases) and 18 lpmos. c. thermophilum contain fewer glycoside hydrolase proteins with higher specific activity if we compare with t. reesei recent industrial host. sometimes it is difficult to grow the fungus on untreated biomass because some fungi optimized for higher cellulases production by using soluble sugars such as lactose (in case of t. reesei) but c. thermophilum which grows in high temperature and cellulose-rich habitats, can generate soluble by degrading crystalline cellulose. c. thermophilum has served as a good resource for thermostable eukaryotic proteins. however, these proteins required expression of c. thermophilum genes in heterologous mesophilic expression systems, as c. thermophilum has not yet been amenable for genetic manipulation. therefore c. thermophilum has great significance for industrial application after strain improvement for protein production and secretion. c. thermophilum cellulase protein secretion start decreasing after few days of induction, so to overcome this problem we characterised a thermostable, ionic liquid tolerant cellobiohydrolase from gh6 family which hydrolyses avicel, cmc, β-glucan, in a processive manner and produces cellobiose. this enzyme exhibits tolerance towards cellobiose and glucose, it is more sensitive to cellotriose, as its activity decreases upto 40 % in presence of 15 mm cellotriose, it also shows stronger binding towards cellotriose. so, we increase the catalytic efficiency of this by site direct mutagenesis by decreases the binding of cellotriose into the catalytic cleft. we are also trying to express this modified enzyme in to c. thermophilum. another approach to increase the protein expression in host is promoter engineering. mig1 is gene which produce mig1 protein which expression in presence of glucose and repress the production of cellulase by bind to the promoter region interfere with the transcription of the cellulase. we found binding site of mig1 protein the same cellobiohydrolase gene, so we are replacing the promoter region by homologous recombination of the cellobiohydrolase gene in c. thermophilum to increase the protein production at transcription level. this study help us to understand the cellulase gene expression in c.thermophilum.