2Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142292, Moscow Region, Russia; fax: (7-095) 923-3602
3Institute of Genetics, Moscow 113545, Russia
* To whom correspondence should be addressed.
Received March 24, 2003; Revision received April 21, 2003
Recombinant endo-beta-1,4-xylanase (Xyl-31rec, 31 kD, pI 8.2-9.3, the tenth family of glycosyl hydrolases) was isolated from the culture liquid of Penicillium canescens (strain with the amplified homologous xylanase gene) by chromatofocusing on Mono P and hydrophobic chromatography on phenyl-Superose. It is shown that the biochemical and kinetic parameters, substrate specificity, stability, and other properties of the recombinant and native enzymes are almost the same. It was found that Xyl-31rec can be used for biobleaching of cellulose, the recombinant P. canescens strains providing a high yield of extracellular Xyl-31rec (up to 800-900 U/ml of culture liquid) and not secreting cellulases.
KEY WORDS: endo-beta-1,4-xylanase, chromatofocusing, hydrophobic chromatography, recombinant strain, biobleaching of cellulose