Article

Production of laccase from Trametes trogii TEM H2: a newly isolated white-rot fungus by air sampling.

Ege University, Faculty of Science, Biology Department, Basic and Industrial Microbiology Section, Bornova-Izmir, Turkey. , .
Journal of Basic Microbiology (Impact Factor: 1.2). 02/2012; DOI: 10.1002/jobm.201100341
Source: PubMed

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).

0 Bookmarks
 · 
143 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Laccase from Trametes polyzona WR710-1 was produced under solid-state fermentation using the peel from the Tangerine orange (Citrus reticulata Blanco) as substrate, and purified to homogeneity. This laccase was found to be a monomeric protein with a molecular mass of about 71 kDa estimated by SDS-PAGE. The optimum pH was 2.0 for ABTS, 4.0 for L-DOPA, guaiacol, and catechol, and 5.0 for 2,6-DMP. The Km value of the enzyme for the substrate ABTS was 0.15 mM, its corresponding Vmax value was 1.84 mM min(-1) , and the kcat /Km value was about 3960 s(-1) mM(-1) . The enzyme activity was stable between pH 6.0 and 8.0, at temperatures of up to 40 °C. The laccase was inhibited by more than 50% in the presence of 20 mM NaCl, by 95% at 5 mM of Fe(2+) , and it was completely inhibited by 0.1 mM NaN3 . The N-terminal amino acid sequence of this laccase is AVTPVADLQISNAGISPDTF, which is highly similar to those of laccases from other white-rot basidiomycetes.
    Journal of Basic Microbiology 06/2013; · 1.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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.

Full-text

View
1 Download
Available from
Aug 12, 2014