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Isolation and
characterization of a new keratinolytic bacterium that
exhibits significant feather-degrading capability
Bo Xu1,2,3#, Qiaofang Zhong1,4#,
Xianghua Tang1,2,3, Yunjuan Yang1,2,3
and Zunxi Huang1,2,3*
1School
of Life Science, Yunnan Normal University, Kunming, 650092,
P.R. China.
2Key
Laboratory of Yunnan for Biomass Energy and Biotechnology of
Environment, Yunnan, Kunming, 650092, P.R. China.
3Engineering
Research Center of Sustainable Development and Utilization
of Biomass Energy of Ministry of Education, Yunnan Normal
University, Kunming, 650092, P.R. China.
4Institute
of Biotechnology, Yunnan Agricultural Academy, China.
*Corresponding author
E-mail:
huangzunxi@163.com. Fax: 86-0871-5847822.
#These
authors contributed equally to this paper
Accepted 11
June, 2009 |
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A novel
bacterium,
Bacillus
licheniformis
K-19, which produces a large amount of a keratinase
that is extremely thermostable
and has a broad resistance to pH, was isolated
and
characterized.
The maximum amount of keratinase activity (about 224 Uml-1)
was produced
at
37°C
when the bacterium was cultured for 72 h in broth containing
feather meal with initial pH of 7.5. The keratinase activity
was observed over a wide range of temperatures (30 - 90°C)
and pH values (pH
6 - 10).
It
was optimal
at 60°C and
pH 7.5 - 8 respectively.
These
results suggest potential biotechnological applications of
this bacterium that involve hydrolysis of keratin, including
the improvement of the nutritional properties of feathers
(and other keratins) used as supplementary feedstuffs.
Key
words:
Bacillus licheniformis, chicken feather, keratin,
keratinolytic protease. |
