Cellulase

CHAPTER ONE

1.0 CELLULASE

Cellulase refers to a class of enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis (i.e. the hydrolysis of cellulose). However, there are also cellulases produced by a few other types of organisms, such as some termites and the microbial intestinal symbionts of other termites. Several different kinds of cellulases are known, which differ structurally and mechanistically. The EC number for this group of enzymes is EC 3.2.1.4.

Reaction: Hydrolysis of 1,4-beta-D-glycosidic linkages in cellulose, lichenin and cereal beta-D-glucans.

Other names for 'endoglucanases' are: endo-1,4-beta-glucanase, carboxymethyl cellulase (CMCase), endo-1,4-beta-D-glucanase, beta-1,4-glucanase, beta-1,4-endoglucan hydrolase, and celludextrinase. The other types of cellulases belong to exocellulases. Beta-glucosidases can also be considered as yet another group of cellulases. The expression 'avicelase' refers to the total cellulase activity of a given sample of the enzyme(s). The cellulase may be the result of the action of more than one type of enzymes.

Model of cellulase enzyme, produced by T. fusca, based on PDB structure 1JS4

STRUCTURE OF CELLULASE

Ribbon Representation Of The Streptomyces Lividans Beta-1,4-endoglucanase Catalytic Domain – An Example From The Family 12 Glycoside Hydrolase.

2.0 CHAPTER TWO

TYPES AND ACTION OF CELLULASE

There are different types and action of cellulose depending on the type of reaction catalyzed and they are:

* Endocellulase breaks internal bonds to disrupt the crystalline structure of cellulose and expose individual cellulose polysaccharide chains.

* Exocellulase cleaves two to four units from the ends of the...