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Isolation and
characterization of a novel Bacillus subtilis WD23
exhibiting laccase activity from forest soil
Chun-lei Wang, Min Zhao*, De-bin Li,
Dai-zong Cui, Lei Lu and Xing-dong Wei
College of
Life Sciences, Northeast Forestry University, No. 26,
He-Xing Road, Harbin, Heilongjiang 150040, P.R. China.
*Corresponding author.
E-mail:
82191513@163.com. Tel:
86-451-82191513. Fax: 86-451-82191513.
Abbreviations: RBBR,
Remazol brilliant blue R; LB, Luria-Bertani; PCR,
polymerase chain reaction; BLAST, basic local
alignment search tool.
Accepted 29
July, 2010 |
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The strain
Bacillus sp. WD23 exhibiting laccase activity was
screened from forest soil. The M9 medium containing Cu2+
was used for enriching and isolating bacterial strains
capable of oxidizing syringaldazine. One isolated strain was
identified as Bacillus subtilis WD23 based on the
results of physiological and biochemical tests and 16S rDNA
sequence analysis. The strain WD23 could grow at
temperatures ranging from 20 to 55°C and showed optimum
growth temperature and pH at 25°C and 7.0, respectively. The
sporulation rate of the strain clearly correlated well with
the laccase activity. The temperature half-life of the spore
laccase was 2.5 h at 80°C and the pH half life time was 15 d
at pH 9.0. Its spore laccase could decolorize 50 - 90% of
Remazol brilliant blue R (RBBR), alizarin red, congo red,
methyl orange and methyl violet, which suggests the
potential application of spore laccase in dyestuff
treatment.
Key
words:
Bacterial laccase, Bacillus subtilis, spore,
decolorization. |
