Objective:
Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile,
laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at
alkaline conditions are scarce.
Methods:
High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria,
which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing.
Results:
The optimum pH and temperature for CMCase reaction were 8.0 and 55°C, respectively. Alkaline
CMCase was stable over wide pH (3.0-10.6) and temperature (25-55°C) ranges. Enzyme activity
was significantly inhibited by the bivalent cations Mn2+
and Cu2+, and was activated by Fe2+. To improve
the alkaline CMCase production of SX9-4, fermentation parameters were selected through onefactor-
at-a-time and further carried out by response surface methodologies based on a central composite
design.
Conclusion:
High CMCase production (57.18 U/mL) was achieved under the optimal conditions:
10.53 g/L carboxymethylcellulose sodium, 7.74 g/L glucose, 13.71 g/L peptone, and 5.27 g/L ammonium
oxalate.
Biocontrol of Sugarcane Smut Disease by Interference of Fungal Sexual Mating and Hyphal Growth Using a Bacterial Isolate
