Optimization of xylanase production from Melanocarpus albomyces using wheat straw extract and its scale up in stirred tank bioreactor

摘要

Production of xylanase from agro-industrial by-product such as wheat straw has been optimized. The wheat straw is subjected to heat treatment under mild alkaline conditions for the extraction of xylo-oligosaccarides, which serve as both an inducer and a carbon source for fungal growth and xylanase production under submerged fermentation, The statistical approach of response surface methodology has been employed for the optimization of different nitrogen sources. The production of xylanase is influenced by the synergic effect of nitrogen sources in the fermentation medium. Further optimization of other factors such as inoculum age, inoculum size, initial pH, growth temperature and agitation significantly enhance xylanase activity to about 425 + 5 IU/mL in shake flask using optimized fermentation medium and conditions. The scale up of fermentation process up to 14 L bioreactor yields a maximum xylanase activity of about 520 IU/mL in 36 h of fermentation which is 1.22-fold higher than that obtained at shake flask level.