Production of laccase from Trametes trogii TEM H2: a newly isolated white-rot fungus by air sampling.
ABSTRACT This work represents the first report of isolation of potential laccase producers by air sampling using media supplemented with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) and guaiacol for laccase production and secretion indicators. Nine fungal isolates showed positive reactions with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) and guaiacol. The isolate named TEM H2 exhibited the largest and intensive oxidation zones with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) (85 mm) and guaiacol (66 mm) and therefore it was selected for detailed investigations. The strain was identified as Trametes trogii TEM H2 due to the morphological characteristics and the comparison of internal transcribed spacer ribosomal DNA gene sequences. The laccase production was screened in different liquid cultures. The best laccase production medium was determined as soluble starch yeast extract medium in which laccase production was reached to a maximum level (989.6 U l(-1) ) on the 8(th) day of cultivation. Effects of different initial pH values on laccase production were tested. Optimum pH value for laccase production in soluble starch yeast extract medium was determined as pH 3.0 with 15425.0 U l(-1) laccase production at 12(th) day of cultivation. In addition, effects of eight inducers (veratryl alcohol, ferulic acid, 1-Hydroxybenzotriazole, syringic acid, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate), 1 mmol l(-1) CuSO(4) , 3% ethanol, guaiacol) were examined. Only cultures with 2,5-xylidine exhibited 1.9 fold increase in laccase activity reaching to 28890.0 U l(-1) . (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
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ABSTRACT: Laccase production by a temperature and pH tolerant fungal strain (GBPI-CDF-03) isolated from a glacial site in Indian Himalayan Region (IHR) has been investigated. The fungus developed white cottony mass on potato dextrose agar and revealed thread-like mycelium under microscope. ITS region analysis of fungus showed its 100% similarity with Trametes hirsuta. The fungus tolerated temperature from 4 to 48°C ± 2 (25°C opt.) and pH 3-13 (5-7 opt.). Molecular weight of laccase was determined approximately 45 kDa by native PAGE. Amplification of laccase gene fragment (corresponding to the copper-binding conserved domain) contained 200 bp. The optimum pH for laccase production, at optimum growth temperature, was determined between 5.5 and 7.5. In optimization experiments, fructose and ammonium sulfate were found to be the best carbon and nitrogen sources, respectively, for enhancing the laccase production. Production of laccase was favored by high carbon/nitrogen ratio. Addition of CuSO4 (up to 1.0 mM) induced laccase production up to 2-fold, in case of 0.4 mM concentration. Addition of organic solvents also induced the production of laccase; acetone showed the highest (2-fold) induction. The study has implications in bioprospecting of ecologically resilient microbial strains.Enzyme research. 01/2013; 2013:869062.
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ABSTRACT: Laccases are environmentally friendly alternatives in many important applications such as in bioremediation, biopulping, textile, and the food industry. They have wide substrate specificity, can oxidize a broad range of compounds, and show potential for use in various industrial processes. Therefore, developing methods to increase laccase production is important. In the current study, we aimed to identify optimum conditions for inducing laccase production in the basidiomycete Lentinus crinitus cultivated under varying nitrogen concentrations and in the presence of potential inducers of laccase production, including copper and phenolic compounds. Peak enzymatic activity (11,977 U/L) occurred at higher nitrogen concentrations (2.8 g/L nitrogen). Regardless of the nitrogen concentration, addition of copper increased the laccase activity and decreased mycelial growth, with maximum laccase activity (14,320 U/L) observed at the highest nitrogen concentration combined with 150 mM CuSO4. In addition, ethanol (0.5 or 1.0 mM) and guaiacol (1.5 mM) increased laccase production to 15,000, 14,800, and 14,850 U/L, respectively. Our findings highlighted the optimum conditions for producing L. crinitusderived laccase as potential alternatives to the conventional production and application of the enzyme.Genetics and molecular research: GMR 10/2014; 13(4):8544-8551. · 0.99 Impact Factor
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ABSTRACT: Laccases are blue multicopper oxidases, which catalyze the monoelectronic oxidation of a broad spectrum of substrates, for example,ortho-andpara-diphenols, polyphenols, aminophenols, and aromatic or aliphatic amines, coupled with a full, fourelectron reduction of O 2 to H 2 O. Hence, they are capable of degrading lignin and are present abundantly in many white-rot fungi. Laccases decolorize and detoxify the industrial effluents and help in wastewater treatment. They act on both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants, and they can be effectively used in paper and pulp industries, textile industries, xenobiotic degradation, and bioremediation and act as biosensors. Recently, laccase has been applied to nanobiotechnology, which is an increasing research field, and catalyzes electron transfer reactions without additional cofactors. Several techniques have been developed for the immobilization of biomolecule such as micropatterning, selfassembled monolayer, and layer-by-layer techniques, which immobilize laccase and preserve their enzymatic activity. In this review, we describe the fungal source of laccases and their application in environment protectioEnzyme Research. 05/2014;