LIGNINOLYTIC FUNGI

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            Ligninolytic fungi are taxonomically heterogeneous higher fungi characterized by a unique ability to de-polymerize and mineralize lignin. They include wood-and soil-inhabiting Basidiomycetes and some Ascomycetes. The extracellular, non-specific and oxidative enzymatic system of these fungi catalyzes lignin degradation. This system includes lignin peroxidase, Mn-peroxidase, versatile peroxidase and laccase, allowing the degradation of many persistent aromatic compounds with structures similar to those of the metabolites formed in the biosynthesis or degradation of lignin. Among such compounds are both individual substances [pesticides, polychlorinated biphenyls, halogenated aromatic compounds, nitro- and amino-substituted phenols, trinitrotoluene, synthetic dyes and Polycyclic Aromatic Hydrocarbons (PAHs)] and their complex mixtures.
            Enzyme synthesis is not repressed when the concentrations of these substances are too low to induce the enzymes. Therefore, the enzymes can degrade even low concentrations of pollutants. The catalytic action of the Ligninolytic enzymes gives rise to polar and water-soluble products, which are more accessible for both fungal metabolism and further degradation by the natural soil micro flora.
            IMPORTANCE
            Ligninolytic fungi are a microorganism group of significant biotechnological value, due to their ability to degrade a variety of lingo-cellulose substrates, together with agroindustrial wastes and toxic organic effluents, resulting to their complete degradation.
            With the use of these microorganisms, valorization of agro-industrial wastes is possible, through the isolation of valuable dietary polysaccharides from the fungal biomass. Ligninolytic fungi are also a valuable resource of industrially relevant biocatalysts, the enzymes responsible for the microbial lingo-cellulose degradation.
            Ligninolytic oxidoreductive enzymes are widely used for a variety of applications, industrial or other, while their use in bioremediation is of great importance.
            The organic synthesis of value-added chemicals with the use of environmentally-friendly biocatalyst processes, aiming at the cost–effective production of compounds with possible use in the pharmaceutical or polymer industry, is an alternative to the troublesome chemical synthesis of organic compounds already in practice.
            Currently, ligninolytic oxido-reductive enzymes are used extensively in organic synthesis applications, while most research efforts seem to take advantage of the low selectivity that these catalysts exhibit towards the oxidized substrate, to produce various products with heterogeneous structure, customized to meet specific needs, with the use of a single enzyme.

Prema Iswary,               
Assistant Professor,     
Department of Botany.
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