Title:Screening of an Alkaline CMCase-Producing Strain and the Optimization of its Fermentation Condition
Volume: 21
Issue: 13
Author(s): Junmei Zhou, Lianghong Yin*, Chenbin Wu, Sijia Wu, Jidong Lu, Hailing Fang and Yongchang Qian*
Affiliation:
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300,China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300,China
Keywords:
Alkaline CMCase, screening, identification, enzyme characteristics, optimization, fermentation.
Abstract:
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.