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PRODUCTION OF
CELLULASES FROM ALTERNARIA SP. MS28 ANDTHEIR PARTIAL
CHARACTERIZATION
MUHAMMAD SOHAIL, AQEEL
AHMAD AND SHAKEEL AHMED KHAN*
Abstract:
Cellulase production
was studied after cultivation of Alternaria sp. MS28 in cellulose
containing media. This fungus produces different component activities of
cellulases, a property influenced by growth temperature. The data
indicates that the production of cellulases is a genetically regulated
process in the Alternaria sp. MS28, where endoglucanase
production was triggered in the presence of CMC; β-glucosidase
production by salicin; however, the presence of glucose suppressed the
cellulase production. The growth and cellulase production kinetics
revealed that the production of endoglucanase and β-glucosidase started
in early log-phase and attained its peak in stationary phase. The higher
rates of biomass production and shorter generation time were noted in
SDB. The rate of endoglucanase and β-glucosidase production was higher
in CMC and salicin containing medium, respectively. Partial
characterization of cellulases in cell-free culture supernatant showed
that endoglucanase has its optimum activity at 50oC and pH
6.0; while β-glucosidase at 45oC and pH 4.5. The melting
temperature for endoglucanase and β-glucosidase were 57o and
59oC, respectively. Activity of both the enzymes was slightly
affected by the presence of EDTA indicating that these enzymes may not
require divalent metallic ions for their activity.
Department of Microbiology, University of Karachi, Karachi-75270,
Pakistan
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