Preliminary studies on enzymatic deinking

IV Iberian Congress on Biotechnology; I Ibero-American Meeting on Biotechnolog

Characterisation and application of glycanases secreted by aspergillus terreus CCMI 498 and trichoderma viride CCMI 84 for enzymatic deinking of mixed office wastepaper

Two enzymatic extracts obtained from xylan-grown Aspergillus terreus CCMI 498 and cellulose-grown Trichoderma viride CCMI 84 were characterised for different glycanase activities. Both strains produce extracellular endoxylanase and endoglucanase enzymes. The enzymes optimal activity was found in the temperature range of 45-60 ºC. Endoglucanase systems show identical activity profiles towards temperature, regardless of the strain and inducing substrate. Conversely, the endoxylanases produced by both strains showed maximal activity at different pH values (from 4.5 to 5.5), being the more acidic xylanase produced by T. viride grown on cellulose. The endoglucanase activities have an optimum pH at 4.5-5.0. The endoxylanase and endoglucanase activities exhibited high stability at 50 ºC and pH 5.0. Mannanase, β-xylosidase, and amylase activities were also found, being the first two activities only present for T. viride extract. These two enzymatic extracts were used for mixed office wastepaper (MOW) deinking. When the enzymatic extract from T. viride was used, a further increase of 24% in ink removal was obtained by comparison with the control. Both enzymes contributed to the improvement of the paper strength properties and the obtained results clearly indicate that the effective use of enzymes for deinking can also contribute to the pulp and paper properties improvement.PRAXIS/BIO/1133/95. BIC/3087/96, BD/3253/96

Induction of xylanolytic activity by Aureobasidium pullulans using xerographic paper

PRAXIS/BIO/1133/95

Preliminary studies on enzymatic applications in the paper industry

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Screening new enzymes for enzymatic deinking

[Excerpt] Introduction: The deinking process involves the ink particles dislodgement from the fibre surface and the separation of the dispersed ink. The use of enzymes is generally related either to the fibre surface or the ink particles attack (I ,2 ,3 ,4 ). For that matter, enzymatic deinking is known to greatly depend on the pulp characteristics, namely the chemical composition of the fibre and ink particles and the printing process involved, which defines the fibre/ink interactions. Additionally, other variables influence the process (consistency, pH, temperature, mixing), which cannot be ignored (3,5,6,7). In the present work several xylanolytic and cellulolytic enzymes with potential affinity to fibre constitutive were produced and preliminary characterised so that their contribution to the deinking of a mixed office wastepaper sample could be evaluated. [...

Induction of xylanolytic activity in Aureobasidium pullulans using xerographic paper

The possibility of using cheaper culture media for endo-1,4-b-xylanase production by the color variant-derivative strain of Aureobasidium pullulans Y-2311-1, one of the known best producers of this activity, was investigated. Of all the studied alternative substrates, xerographic paper showed to be the best inducer of xylanolytic activity of this strain, using different carbon sources. The highest extracellular xylanase activity obtained was 15 U/mL when using lactose as the carbon source in the presence of xerographic paper

Preliminary studies on enzimatic applications in the paper industry

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