A comparative study of Thermomyces lanuginosus strains on thermostable xylanase production

Strains of Thermomyces lanuginosus could be differentiated into two groups based on their ability to produce xylanase using xylan or xylose as sole of carbon source. One group of these strains produced high xylanase activity either in the medium using xylan or xylose as a sole of carbon source. The xylanase production by T. lanuginosus ATCC 44008, THKU-11, and THKU-25, which were the representative members of this group, increased when xylose was added to the xylan medium. In contrast, there was another group that produced high xylanase activity only in the xylan medium. Addition of xylose to the xylan medium resulted decreasing of xylanase production in T. lanuginosus ATCC 46882, TISTR 3465 and THKU-85 that belonged to this group. The finding indicated that induction and repression mechanism of xylose on xylanase expression was different among the strains of T. lanuginosus. In addition, phylogenetic analysis obtained from random amplified polymorphic DNA (RAPD) pattern using primer UBC 241 pointed to greater diversity of high and low xylanase producing strains using xylose as a carbon source.