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CELLULASE
Cellulase refers to a family of enzymes which act in
concert to hydrolyze cellulose.
Cellulases are widely distributed throughout the
biosphere and are most manifest in fungal and microbial
organisms.
At
least two steps in cellulose degradation by microorganisms begin with
the preparatory prehydrolytic first step involving an enzyme (C1)
which swells and/or hydrates anhydroglucose chains. The second step
uses hydrolytic enzymes (Cx) and beta glucosidase (cellobiase).
Trichoderma reesei has an extensively studied cellulase enzyme complex. This complex converts
crystalline, amorphous, and chemically derived celluloses
quantitatively to glucose. The vital characteristics of this
cellulase complex are
1) the system is
multienzymatic;
2) at least three enzyme
components are both physically and chemically distinct;
and
3)
all three components play essential roles in the hydrolysis of
cellulose to glucose. The assay for cellulase activity uses a method which determines the
effect of cellulase on microcrystalline cellulose with respect to
glucose formation.
Released glucose is
determined in a hexokinase/glucose-6-phosphate dehydrogenase system
at 340 nm.
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