New cellulase-free xylanase enzyme - produced by culturing thermomyces lanuginosus on lignocellulose

摘要

New exocellulase- and endocellulase-free xylanase (I) is produced by culturing Thermomyces lanuginosus on a nutrient medium contg. lignocellulose. The T. lanuginosus strain used is specifically DSM 5826. It is cultured on wheat straw, barley chaff, corn cobs or paper pulp at 30-70 (esp. 45-60) deg.C and pH 6-7. USE - (I) is used for digesting hemicelluloses (esp. xylan) in unbleached, semi-bleached or bleached paper pulp. In an example, a medium (300 ml) contg. 9 g ground and dried barley chaff, 3.3 g meat peptone, 0.6 g (NH4)SO4, 0.45 g urea, 0.09 g MgSO4, 0.09 g CaCl2, 4.5 g KH2PO4, 0.3 ml Tween 80 and trace elements was inoculated with a DSM 5826 preculture and shaken at 50 deg.C for 4.5 days. The culture filtrate has a xylanase activity of 222.9 U/ml, a beta-glucosidase activity of 0.6 U/ml, and no detectable carboxymethylcellulase or glucanase activity.