title: Production of beta-xylanase by a Thermomyces lanuginosus MC 134 mutant on corn cobs and its application in biobleaching of bagasse pulp.
abstract: 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.
authors.affiliation: Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, P.O. Box 1334, Durban, South Africa.
authors.forename: Kuttanpillai Santhosh
authors.initials: KS
authors.lastname: Kumar
authors.forename: Ayyachamy
authors.initials: A
authors.lastname: Manimaran
authors.forename: Kugen
authors.initials: K
authors.lastname: Permaul
authors.forename: Suren
authors.initials: S
authors.lastname: Singh
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000201:enzymology* / Q000235:genetics*; D001673:Biodegradation, Environmental; D002482:Cellulose / Q000378:metabolism*; D003116:Color; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D007220:Industrial Waste; D009154:Mutation; D035261:Plant Components, Aerial / Q000382:microbiology*; D013045:Species Specificity; D003313:Zea mays / Q000382:microbiology*
chemical_list: D007220:Industrial Waste; D002482:Cellulose; C027433:bagasse; D043364:Endo-1,4-beta Xylanases