Journal of Industrial Microbiology and Biotechnology

, Volume 24, Issue 6, pp 396–402

Production and characterization of thermostable xylanase and pectinase from Streptomyces sp. QG-11-3


  • Q K Beg
    • Department of Microbiology, Panjab University, Chandigarh-160 014, India
  • B Bhushan
    • MTCC and Gene Bank, Environmental Biotechnology Laboratory, Institute of Microbial Technology, Sector 39-A, Chandigarh-160 036, India
  • M Kapoor
    • Department of Microbiology, Panjab University, Chandigarh-160 014, India
  • G S Hoondal
    • Department of Microbiology, Panjab University, Chandigarh-160 014, India

DOI: 10.1038/sj.jim.7000010

Cite this article as:
Beg, Q., Bhushan, B., Kapoor, M. et al. J Ind Microbiol Biotech (2000) 24: 396. doi:10.1038/sj.jim.7000010

Streptomyces sp. QG-11-3, which produces a cellulase-free thermostable xylanase (96 IU ml−1) and a pectinase (46 IU ml−1), was isolated on Horikoshi medium supplemented with 1% w/v wheat bran. Carbon sources that favored xylanase production were rice bran (82 IU ml−1) and birch-wood xylan (81 IU ml−1); pectinase production was also stimulated by pectin and cotton seed cake (34 IU ml−1 each). The partially purified xylanase and pectinase were optimally active at 60°C. Both enzymes were 100% stable at 50°C for more than 24 h. The half-lives of xylanase and pectinase at 70, 75 and 80°C were 90, 75 and 9 min, and 90, 53 and 7 min, respectively. The optimum pH values for xylanase and pectinase were 8.6 and 3.0, respectively, at 60°C. Xylanase and pectinase were stable over a broad pH range between 5.4 and 9.4 and 2.0 to 9.0, respectively, retaining more than 85% of their activity. Ca2+ stimulated the activity of both enzymes up to 7%, whereas Cd2+, Co2+, Cr3+, iodoacetic acid and iodoacetamide inhibited xylanase up to 35% and pectinase up to 63%; at 1 mM, Hg2+ inhibited both enzymes completely. Journal of Industrial Microbiology & Biotechnology (2000) 24, 396–402.

Keywords: xylanase; pectinase; thermostable; Streptomyces sp

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© Society for Industrial Microbiology 2000