The Optimization Of Trichoderma Reesei FST-1Cellulase Production And Conditions For Ethanol Fermentation

A reliable and sustainable energy source is one of the most concerned issue in theworld today. The increase of petroleum price and aggravating environmental problemsdemands the seek for new energy sources. Lignocellulosic ethanol is regarded as thebest candidate replacing fossil fuel in the future for a number of reasons:lignocellulose is the most abundant renewable biomass and ethanol is a clean energyresource that’s friendly to the environment. These considerations have made theresearch of lignocellulosic ethanol the most important investigation globally. InChina, most of the agricultural residues containing lignocellulose are burnt, resultingin the waste of these valuable energy resources and causing serious pollution to theatmosphere. The development of lignocellulosic industry is the best way to preventthese problems to occur. The high price of cellulases is the bottleneck for thisindustry to become economically viable, and increase the production of cellulases andoptimizing the cellulase system is the key to solve these problems.In this thesis, the media and conditions for cellulase production by the cellulaseworkhorse Trichoderma reesei FST-1was optimized. The comparison of enzymeproduction from six types of media leads to the identification of the media resulting inthe highest filter paper activity and protein production. By investigating the impactof inoculation time, temperature and initial pH, the conditions for enzyme productionwas optimized. The filter paper activity and protein production level after theseoptimization reached documented levels from literature.The saccharification and ethanol production level was investigated by usingeither FST-1enzymes or a cocktail of FST-1and Aspergillus aculeatus ZLF enzymesusing deligninated corncob residues. A significant improvement of saccharificationand ethanol production was observed when the cocktail was used over when onlyFST-1enzymes were used. Over90%of cellulose was converted to glucose, and theethanol yield was about50%. Only20mg/g cellulase was used to achieve this level ofyield, agreeing with the requirement of industrial production, and setting the basis forfurther investigation of lignocellulosic ethanol production...