کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
22176 | 43259 | 2009 | 5 صفحه PDF | دانلود رایگان |
The production of hemicellulases by Thermomyces lanuginosus SK using oatspelts xylan was examined during submerged cultivation. A high level of extracellular xylanase (346 ± 10 U ml− 1) production was observed on the fifth day; however, accessory enzyme levels were low. T. lanuginosus SK was further subjected to UV and N-methyl-N-nitro-N-nitrosoguanidine mutagenesis. The T. lanuginosus MC 134 mutant showed a 1.5 fold increase in xylanase production on oatspelts xylan, compared to the wild type strain. Xylanase production was further enhanced to 3299 ± 95 U ml− 1 by using corn cobs under optimized growth conditions. A reduction in xylanase production was observed in a 5 L fermenter. Also, the biobleaching efficiency of crude xylanase was evaluated on bagasse pulp, and a brightness of 46.07 ± 0.05% was observed with the use of 50 U of crude xylanase per gram of pulp. This brightness was 3.6 points higher than that of the untreated samples. Reducing sugars (25.78 ± 0.14 mg g− 1) and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. T. lanuginosus MC 134 has a potential application in the pulp and paper industries.
Journal: Journal of Bioscience and Bioengineering - Volume 107, Issue 5, May 2009, Pages 494–498