| Most of post work on cellulase structures and its functions was focused on how to enhance its biomass lignocellulosic decomposability, which needed many groups of cellulase to synergic action. Recently it was paid more attention to the application of cellulase on modification of plant fibre. Many results showed that endoglucanase(EG) played key role on modification of plant fibre. Because of diversity of nature cellulase sources, complexity of multi-components and difficult of separation , application of single cellulase component was much restricted. EGI one kind of endoglucanase was obtained by gene engineering as recombinant enzyme. Due to its high activity, high purity, optimal pH value 7.5 and convenient production, EGI had brilliant future on modification of plant cellulose. But further study was still needed for EGI final effective application.In this paper major work was done on the construction of expression vector containing of endoglucanase EGI-CD and it's heterogeneous expression in Pichia pastoris. With the comparison of adsorption and hydrolysis of different substrates by EGI and EGI-CD, the influcence of CBD on the adsorption and on its hydrosis of enzyme on substrates were discussed in order to improve its more economically application of EGI on the industrial condition with good modification efficiency. Major results as following:1. EGI-CD was successfully obtained by gene engineering, and used as material for the study of the influence of the CBD on adsorption and specificities of EGI on different substrates.2. Adsorption of cellulase on insoluble cellulose was depended on the structures of substrates.The influcence of CBD on adsorption of EGI on cellulose was positively relation to crystallization of cellulose. The percentages adsorption of EGI or EGI-CD on swollen cellulose, filter paper and crystalline cellulose were 64.2%, 43.5%, 33.6% or 38.8%, 14.5%, 0, respectively. The results indicated deletion of CBD decreased adsorption rate of EGI on insoluble cellulose substrate. Such results provided direction for EGI evolution by gene engineering.3. Hydrosis of insoluble cellulose by EGI mainly lied on the adsorption of enzyme on substrates. The adsorption of EGI-CD without CBD only provided the contact opportunity of enzyme and substrates. While the adsorption of EGI with CBD not only provided the contact opportunity of enzyme and substrates, but also caused the cellulos structure alteration. Although such alteration could not result in the hydrosis of substrates directly, it promoted the hydrosis of catalytic domain of enzyme.4. EGI could release reducing sugar from cellulose within short time. But with the timeincrease, the quantity of reducing sugar trended stabilization. These results showed EGI just attacked on cellulose surface, indicated EGI had the characteristic for modification of plant cellulose.5. EGI could obviously improve the deinking efficiency of mixed office waste (MOW). The pretreatment of NaOH before deinking could make deinking efficiency more than 90%. EGI treatment improved the surface properties of denim fabric with more snowflake, more third dimension and better color, but no effect on the strength of denim fabric.
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