Thermostable, alkalophilic and cellulase free xylanase production by Thermoactinomyces thalophilus subgroup C

Thermoactinomyces thalophilus produced cellulase free extracellular endo-1, 4-beta -xylanase (EC 3.2.1.8) at 50 degreesC and pH 8.5. Maximum xylanase p roduction was thieved in fermentation medium using birchwood xylan as subst rate after 96 h of growth at 50 degreesC. Other agricultural substrates suc h as wheat bran, wheat straw, sugarcane bagnsse and cornstover produced les s xylanase, The crude enzyme preparation from mutant T. thalophilus P2 grow n under optimised fermentation conditions showed no cellulase contamination and maximum xylanase activity of 42 U/ml at 65 degreesC and pH 8.5-9.0. Th is enzyme with initial sylanase activity of 42 U/ml was found thermostable up to 65 degreesC and retaining 50% of its activity after its incubation fo r 125 min at 65 degreesC. (C) 2001 Elsevier Science Inc. All rights reserve d.