Hyper production of cellulase-free xylanase by Thermomyces lanuginosus SSBP on bagasse pulp and its application in biobleaching.

A cellulase-free xylanase production by Thermomyces lanuginosus SSBP using bagasse pulp was examined under submerged (SmC) and solid-state cultivation (SSC). Higher level of xylanase activity (19,320 +/- 37 U g(-1) dried carbon source) was obtained in SSC cultures than in SmC (1,772 +/- 15 U g(-1) dried carbon source) after 120 h with 10% inoculum. The biobleaching efficacy of crude xylanase was tested on bagasse pulp, and the maximum brightness of 46.1 +/- 0.06% was observed with 50 U of crude xylanase per gram of pulp, which was 3.8 points higher than the brightness of untreated samples. Reducing sugars (26 +/- 0.1 mg g(-1)) and UV-absorbing lignin-derived compounds in the pulp filtrates were observed as maximum in 50 U of crude xylanase-treated samples. T. lanuginosus SSBP has potential applications due to its high productivity of xylanase and its efficiency in pulp bleaching.