If cellulose can be effectively hydrolyzed intoglucose by cellulase,the production costs of hydrogen,ethanol or other chemicals from cellulosic materials will begreatly decreased,and economically viable production ofb...If cellulose can be effectively hydrolyzed intoglucose by cellulase,the production costs of hydrogen,ethanol or other chemicals from cellulosic materials will begreatly decreased,and economically viable production ofbiohydrogen and bioethanol will become feasible.Celluloseis degraded into glucoses by multi-component enzymesystems.Nowadays cellulases are widely used in brewing,food,bioenergy,fodder,textiles,paper,pharmaceuticals,environmental protection and other industries.However,existing cellulases have several problems that limit theirwider applications,including the low turnover number forsolid cellulosic materials,and low stability in adapting tovarious application conditions.For example,high temperature,low pH,and so on.Application of directedevolution technology may be one of the most effectiveways for improving the characteristics of cellulases.Thispaper presents a brief review of the cellulases hydrolysismechanism by cellulase,advances in cellulases(endoglucanaseandβ-glucosidase)improvement by directedevolution for several characteristics(for instance,thermalstability,pH adaptability and enzyme activity),limitationsof directed evolution for cellulases,and the outlook fordirected evolution for cellulase.展开更多
基金This research was supported by the National Natural Science Foundation of China(Grant No.30870037)Research Fund for the Doctoral Program of Higher Education of China(No.20102329120002)China Postdoctoral Science Foundation(No.20090450983).
文摘If cellulose can be effectively hydrolyzed intoglucose by cellulase,the production costs of hydrogen,ethanol or other chemicals from cellulosic materials will begreatly decreased,and economically viable production ofbiohydrogen and bioethanol will become feasible.Celluloseis degraded into glucoses by multi-component enzymesystems.Nowadays cellulases are widely used in brewing,food,bioenergy,fodder,textiles,paper,pharmaceuticals,environmental protection and other industries.However,existing cellulases have several problems that limit theirwider applications,including the low turnover number forsolid cellulosic materials,and low stability in adapting tovarious application conditions.For example,high temperature,low pH,and so on.Application of directedevolution technology may be one of the most effectiveways for improving the characteristics of cellulases.Thispaper presents a brief review of the cellulases hydrolysismechanism by cellulase,advances in cellulases(endoglucanaseandβ-glucosidase)improvement by directedevolution for several characteristics(for instance,thermalstability,pH adaptability and enzyme activity),limitationsof directed evolution for cellulases,and the outlook fordirected evolution for cellulase.
