title: Biochemical evaluation of xylanases from various filamentous fungi and their application for the deinking of ozone treated newspaper pulp.
abstract: Filamentous fungi, Aspergillus oryzae MDU-4 was biochemically selected among different species of Aspergillus and Trichoderma, for xylanase production. The enzyme activity and specific activity of partially purified xylanase from A. oryzae MDU-4 was 7452 IU/ml and 13,549 IU/g, respectively. Temperature and pH optima for xylanase were found to be 60°C and 6.0, respectively. The reaction kinetics of xylanase was found to be Km (3.33 mg/ml) and Vmax (18,182 μmol/mg). The implementation of ozone treatment in the deinking of newspaper pulp resulted in high crystallinity index (72.1%) and more fibrillar surface. Furthermore, the xylanase treated pulp showed significant improvement in optical properties such as brightness (57.9% ISO) and effective residual ink concentration (211 ppm). Scanning electron microscopy analysis suggests perforations in xylanase treated pulp samples. Here we report biochemical evaluation of xylanases and a combination of ozone treatment followed by catalytically efficient fungal xylanase selected for the cost competitive deinking of newspaper pulp.
authors.affiliation: Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India.
authors.forename: Preeti
authors.initials: P
authors.lastname: Chutani
authors.affiliation: Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India. Electronic address: kekulsharma@gmail.com.
authors.forename: Krishna Kant
authors.initials: KK
authors.lastname: Sharma
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D007281:Ink; D010126:Ozone / Q000737:chemistry* / Q000494:pharmacology; D010209:Paper; D013499:Surface Properties; D013696:Temperature; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D010126:Ozone; D043364:Endo-1,4-beta Xylanases
keywords: Acetone (Pub Chem CID: 180); Ammonium sulfate (Pub Chem CID: 6097028); Aspergillus; DNSA (Pub Chem CID: 11873); Glacial acetic acid (Pub Chem CID: 176); Magnesium sulfate heptahydrate (Pub Chem CID: 24843); Newspaper pulp; Ozone; Potassium dihydrogen phosphate (Pub Chem CID: 516951); Sodium chloride (Pub Chem CID: 5234); Sodium hydroxide (Pub Chem CID: 14798); Trichoderma; Tween 80 (Pub Chem CID: 5281955); Xylanase; d-Xylose (Pub Chem CID: 644160)