Applied Biochemistry and Biotechnology

, 73:159

Characterization of a Thermotolerant and Alkalotolerant Xylanase from a Bacillus sp.

Authors

  • Susana Marques
    • INETI, IBQTA-Deportamento de BiotecnologiaU. Microbiologia Industrial e Bioprocessos, Azinhoga dos lameiros
  • Luís Alves
    • INETI, IBQTA-Deportamento de BiotecnologiaU. Microbiologia Industrial e Bioprocessos, Azinhoga dos lameiros
  • Sandra Ribeiro
    • INETI, IBQTA-Deportamento de BiotecnologiaU. Microbiologia Industrial e Bioprocessos, Azinhoga dos lameiros
  • Francisco M. Gírio
    • INETI, IBQTA-Deportamento de BiotecnologiaU. Microbiologia Industrial e Bioprocessos, Azinhoga dos lameiros
  • M. T. Amaral-Collaço
    • INETI, IBQTA-Deportamento de BiotecnologiaU. Microbiologia Industrial e Bioprocessos, Azinhoga dos lameiros
Original Articles

DOI: 10.1007/BF02785652

Cite this article as:
Marques, S., Alves, L., Ribeiro, S. et al. Appl Biochem Biotechnol (1998) 73: 159. doi:10.1007/BF02785652

Abstract

In a recent screening for thermophilic bacteria from Azores hot springs, a Bacillus sp strain 3M, exhibiting cellulase-free extracellular xylanolitic activity, was isolated. Further enzyme characterization from liquid cultures grown on birchwood xylan revealed that the endo-l,4-βxylanase retains 100% of activity for at least 3 d at 55°C. At 80°C, it retains 47% of its maximal activity, and the enzyme is still active at 90°C. The optimum pH of the enzyme has a broad pH range, between 6.0 and 7.5, and it is remarkably active for the alkaline region, exhibiting 89% of relative activity at pH 9.O. The enzyme was partially inactivated by different divalent metal ions. Because of its tolerance for high temperature and pH conditions, and the absence of contaminating cellulase activity, the xylanase produced byBacillus sp 3M appears to be attractive for use in the pulp and paper industry. Indeed, the efficiency of the enzyme application to the kraftEucalyptus pulp was studied for bleaching pretreatment, resulting in a moderate increase of pulp bleachability.

Index Entries

Thermotolerant bacteriaalkalotolerant bacteriaBacillusextracellular hydrolasesxylanasexylanbleachabilityenzymatic pulp prebleaching

Copyright information

© Humana Press Inc 1998