Iranian Journal of Microbiology (Jun 2009)
Isolation and characterization of Xylanase producing strain of Bacillus cereus from soil
Abstract
Background and Objectives: Research on Xylanase has markedly increased due to its potential applications in pulping and bleaching processes using cellulose free preparations, textile processes, the enzymatic saccharification of lignocellulosic materials and waste treatment. The present study was aimed at isolation and characterization of xylan degrading strain of Bacillus cereus from soil for production of xylanase. Materials and Methods: Twelve isolates were obtained from soil samples of different areas in the Rajshahi University campus and studied for detection of xylanase activity. One of the strains was identified as Bacillus cereus on the basis of the nucleotide sequence of the 16S rRNA gene which produces xylanase extracellularly. We purified xylanase to homogeneity by a combination of ammonium-sulphate precipitation, DEAE-sepharose, Phenyl-5PW and Hydroxyapatite column chromatography using culture supernatant. Results: The SDS-PAGE gave a single band at 32 kDa. The optimum temperature and pH of the purified enzyme was 40oC and 6.0, respectively. The xylanase hydrolyzed oat spelt xylan, birch wood xylan and beech wood xylan efficiently but showed no activity towards cellulose, CM-cellulose and Avicell pH 101. Conclusion: Thus it was a true and neutral xylanase. The isolation of xylanase from Bacillus cereus is rare.
