Optimization of xylanase production by Thermomyces lanuginosus in solid state fermentation.

Extracellular xylanase production by the thermophilic fungus Thermomyces lanuginosus 195 in solid state fermentation (SSF) was found to be significantly affected by fermentation temperature, duration, and inoculum volume (p < or = 0.001). Optimization of these parameters corresponded to a 21.7% increase in xylanase yield. Maximum activity (2,335 U/g of wheat bran) was obtained when 10 g of wheat bran was inoculated with 10 ml of liquid culture and cultivated at 45 degrees C for 40 h. The influence of supplemental carbon and nitrogen sources (3% w/v) on xylanase production was also assessed. Wheat bran, supplemented with glucose and cellulose, facilitated 10% and 7% increases in relative activity respectively. Ammonium based salts, nitrates, and a number of organic nitrogen sources served only to reduce xylanase production (p < or = 0.005) significantly. The enhanced xylanase titers achieved in the present study emphasize the need for optimizing growth conditions for maximum enzyme production in SSF.