To A Filamentous Fungal Cell Separation And Purification Of The Neutral Cellulase Enzyme Function

Cellulosic biomass is the most abundant organic material that produced by plants and other organisms on our planet.High worldwide demand for energy,unstable and uncertain petroleum sources,and concern over global climate change led to the development of biomass conversion to produce renewable resources.Most of lives involved in these processes are microorganisms,especially filamentous fungi,since they have an efficient secretary system of extra cellular proteins,usually enzymes like celluases,which play a key role in both biomass recalcitrance to degradation in nature and biotechnological process in industry.During last decade,neutral cellulases have been widely used in textile industry, because they had many advantages to traditional acidic cellulase,such as better soft fiber product,efficient process,and not-acidic waste liquid to environment.A filamentous fungus producing neutral cellulases has been isolated from straw.It was identified to be a new species of Stachybotrys sp.by sequencing 18S rRNA gene and ITS gene.Systematic work had been done to improve the fermentation and expression regulation of secreted enzymes was found,especially by Microcrystal Cellulase CF11, powder of corn core and Calcium.Three extra-cellular endoglucanses,EGⅠ,EGⅡand EGⅢ,were checked with molecular weigh of about 40.0kDa,68.2kDa and 18.0kDa respectively.All of the three showed optimal CMCase activity at a neutral pH around 6.0 and 50℃.One endoglucanase,EGI,Which showed the mainly CMCase activity,was purified.Now,we are cloning its cDNA sequence by RT-PCR.We also analysis the sequence from Stachybotyrs and other fungi through bioinformatics methods.The final goal of our research is attempting to reach the expressions of these neutral cellulases in other industrial filamentous fungi,such as Trichoderma Reesei and Saccharomyces cerevisiae,as the endoglucanses have potential application in textile industry.