Laccases are enzymes belong to group of copper-containing polyphenol oxidase that acts on a wide range of substrates. This enzyme is present in many plant species and is widely distributed in fungi including wood-rot fungi, where it is often associated with lignin peroxidase, manganese dependent peroxidase, or both. Because of its importance in bioremediation, effluent decolouration and detoxification of pulp bleaching, fungal isolates were screened for the presence of laccase activity using indicator compound guiacol. Sixteen fungal isolates obtained from biodeteriorated agrowaste and wood samples collected from north Gujarat region of India, among which one of the strains was presumed to be potent depending on its growth characteristics and was identified Alternaria alternata. Laccase activity was determined using ABTS as substrate. Various production parameters like pH, temperature, various carbon sources, nitrogen source, inducers and cations were used to select optimum condition for further increase the production of this enzyme. Maximum laccase activity was obtained with glucose and sucrose as carbon source, 0.2 % ammonium sulphate as nitrogen source and 0.06 % Cu+2 with 1.5 mM veratryl alcohol as inducer under optimized condition.
Key words: Lignocellulose, Guiacol, Laccase, Fungi, Optimization
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