THE KINETICS OF CELLULASE-FREE XYLANASE EXCRETION BY THERMOMYCES-LANUGINOSUS RT9

Thermomyces lanuginosus RT9 was grown in a stirred and aerated reactor for the production of xylan-degrading enzymes and the kinetics of xyl anase and beta-xylosidase secretion investigated. During each fermenta tion, k(L)a decreased with increasing mycelia concentration to the poi nt of cellular disintegration. Although both agitation and aeration ra tes had significant influences on the growth rate as well as on the yi elds and rates of enzymes (xylanase and beta-xylosidase) release, the enzyme secretion kinetics showed a comparable pattern independent of t he operating conditions. Enzyme secretion could be separated into a gr owth phase, during which extracellular xylanase was at low level, and an enzyme release phase, when there was a notable increase in the xyla nase production rate accompanying cellular disintegration.