Blanqueo de pasta kraft con hongos ligninolíticos

There have been proposed the biotechnological processes as an alternative to the chemical bleaching sequences of Kraft cellulose paste (Kraft pulp), either for a reduction in the use of chemical compounds (prebleaching with hemicellulasas) or as a procedure able to carry out the bleaching in an ecological way (bleaching with ligninolitic fungi and their oxidative enzymes). The industrial application of the latter depends mostly on the deep knowledge of the bleaching mechanisms, where extracellular peroxidases and oxidases, produced by fungi and other environmetal factors are jointly implied, as for example, Mn²⁺ and organic acids concentration, oxygen pressure, etc. With the aim to analyze every factor about the biobleaching of Eucaliptus globulus Kraft paste, it was studied the effect of adding different organic acid concentrations (oxalic and glycolic acids) for different Mn⁺² concentrations, the influence of the oxygenation through air or oxygen and the effect of fungus morphology, as free or immobilized mycelium, on the enzymatic activity and the final whiteness of the paste.