Grape stalks as substrate for white rot fungi, lignocellulolytic enzyme production and dye decolorization.

The aim of this work was to evaluate the potential of grape stalks, an agroindustrial waste, for growth and lignocellulolytic enzyme production via solid-state fermentation, using the following three white rot fungi: Trametes trogii, Stereum hirsutum and Coriolus antarcticus. The decolorization of several dyes by the above mentioned cultures was also investigated. Similar values of dry weight loss of the substrate were measured after 60 days (33-43 %).

Layer-by-layer self-assembled osmium polymer-mediated laccase oxygen cathodes for biofuel cells: the role of hydrogen peroxide.

High potential purified Trametes trogii laccase has been studied as a biocatalyst for oxygen cathodes composed of layer-by-layer self-assembled thin films by sequential immersion of mercaptopropane sulfonate-modified Au electrode surfaces in solutions containing laccase and osmium-complex bound to poly(allylamine), (PAH-Os). The polycation backbone carries the Os redox relay, and the polyanion is the enzyme adsorbed from a solution of a suitable pH so that the protein carries a net negative charge. Enzyme thin films were characterized by quartz crystal microbalance, ellipsometry, cyclic voltammetry, and oxygen reduction electrocatalysis under variable oxygen partial pressures with a rotating disk electrode.

Extraction and characterization of polygalacturonase of Fomes sclerodermeus produced by solid-state fermentation.

Polygalacturonase (PG) production by Fomes sclerodermeus using solid-state fermentation (SSF) was carried out. Maximal PG activity (26 U/gdw) was obtained between days 11 and 13 at the end of exponential growth. PG activity in the crude extract was more stable at pH 5-6 and 30 degrees C and had optimum activity at pH 5 and 50 degrees C.

Development of a bioreactor system for the decolorization of dyes by Coriolus versicolor f. antarcticus.

Decolorization of 100 microM malachite green (MG) by Coriolus versicolor f. antarcticus using a two-phase bioreactor, was investigated. In the first phase the decolorization ability of this fungus, growing under conditions of solid-state fermentation (SSF), was proved; in the second phase the capacity of the enzymes present in extracts from the solid residues was exploited.

[Stereum hirsutum (Wild) Pers. action in dye degradation].

Stereum hirsutum, a white rot fungus, has a good growth in solid state fermentation. This was carried on with wheat bran, soy bran and a mixture of both. Mycelia grown on soy bran showed the highest decolorization activity on Ponceau 2R (xylidine), indigo carmine and malachite green.

Stabilization studies of Fomes sclerodermeus laccases.

Stability of laccase isoenzymes from a crude extract obtained from Fomes sclerodermeus grown on wheat bran medium was studied. The variables assessed were temperature, pH and additives. As revealed by PAGE, three bands of laccase, each with different thermal inactivation pattern, were detected in the crude extract: after 6h at 50 degrees C and pH 8, Lc2 was the most resistant, while the Lc1 and Lc3 bands were almost completely inactivated.

[Combined effect of copper and initial pH of the culture on production of laccase and manganese peroxidase by Stereum hirsutum (Willd) Pers].

Stereum hirsutum is a white-rot fungus which produces laccase and manganese peroxidase as part of its ligninolytic system. Maximal ligninases production (under the conditions studied) was obtained in the media containing 250 microM Cu++ along with a pH value of 5.5.

Evaluation of Argentinean white rot fungi for their ability to produce lignin-modifying enzymes and decolorize industrial dyes.

The decolorizing capacity of 26 white rot fungi from Argentina was investigated. Extracellular production of ligninolytic enzymes by mycelium growing on solid malt extract/glucose medium supplemented with different dyes (Malachite Green, Azure B, Poly R-478, Anthraquinone Blue, Congo Red and Xylidine), dye decolorization and the relationship between these two processes were studied. Only ten strains decolorized all the dyes, all ten strains produced laccase, lignin peroxidase and manganese peroxidase on solid medium.

Modification of malachite green by Fomes sclerodermeus and reduction of toxicity to Phanerochaete chrysosporium.

Malachite green (MG) is a triphenylmethane dye used as a fungicide but also possesses a high toxicity to mammalian cells. The toxicity of MG to Fomes sclerodermeus and Phanerochaete chrysosporium was assessed. P.

[Degradation of pine needles by Stereum hirsutum].

Pine-needle degradation by Stereum hirsutum was studied under conditions of solid state fermentation with the aim of accelerating its decomposition, avoiding the accumulation in situ and in view of the possible utilization of the residual organic matter. Three experimental systems were tested: pine needles alone and with the addition of either a nitrogen source or barley grain. Determinations were made at 14 and 28 days of incubation.

Optimization of a culture medium for ligninolytic enzyme production and synthetic dye decolorization using response surface methodology.

A Box-Wilson central composite design was applied to optimize copper, veratryl alcohol and l-asparagine concentrations for Trametes trogii (BAFC 212) ligninolytic enzyme production in submerged fermentation. Decolorization of different dyes (xylidine, malachite green, and anthraquinone blue) by the ligninolytic fluids from the cultures was compared. The addition of copper stimulated laccase and glyoxal oxidase production, but this response was influenced by the medium N-concentration, with improvement higher at low N-levels.

Optimization of manganese peroxidase and laccase production in the South American fungus Fomes sclerodermeus (Lév.) Cke.

Fomes sclerodermeus produces manganese peroxidase (MnP) and laccase as part of its ligninolytic system. A Doehlert experimental design was applied in order to find the optimum conditions for MnP and laccase production. The factors studied were Cu(2+), Mn(2+) and asparagine.

[Degradation of poplar wood by Fomes sclerodermeus: production of ligninolytic enzymes in sawdust of poplar and cedar].

Fomes sclerodermeus is a white-rot fungus. Its production of laccase, manganese peroxidase and lignin peroxidase on sawdust-based media was evaluated. No lignin peroxidase activity was measured in any media tested.

[Enzymatic activity and degradation of different kinds of organic wastes by Saccobolus saccoboloides (Fungi, Ascomycotina)].

The ability to degrade organic solid wastes by the fungus Saccobolus saccoboloides was studied. The organism, unusual in such studies, was cultivated in synthetic liquid media with agitation, and on day 8 of growth the mycelium was passed to flasks with trimming. On day 16 of growth, the trimming degradation was assesed by carboxymethylcellulase, xylanase, and amylase activities evaluation, and NaOH 1% hydrolysis.

Production of laccase and manganese peroxidase by Fomes sclerodermeus grown on wheat bran.

The aim of this work was to study the growth and production of ligninolytic enzymes by Fomes sclerodermeus using a natural medium based on wheat bran as the principal substrate in a solid-state fermentation. Growth was monitored by measuring the chitin content in the substrate. The maximum rate of growth was observed between days 7 and 18.

Degradation of environmental pollutants by Trametes trogii.

The ability of the ligninolytic fungus Trametes trogii to degrade in vitro different xenobiotics (PCBs, PAHs and dyes) was evaluated. Either 200 ppm of a PCB mixture (Aroclor 1150) or 160 ppm of an industrial PAH mixture (10% V/V of PAHs, principal components hexaethylbenzene, naphthalene, 1-methyl naphthalene, acenaphthylene, anthracene, fluorene and phenanthrene), were added to trophophasic and idiophasic cultures growing in a nitrogen limited mineral medium (glucose/asparagine) and in a complex medium (malt extract/glucose). Gas-liquid chromatography proved that within 7 to 12 d more than 90% of the organopollutants added were removed.

Copper induction of lignin-modifying enzymes in the white-rot fungus Trametes trogii.

Trametes trogii, a white rot basidiomycete involved in wood decay worldwide, produces several ligninolytic enzymes, laccase being the dominant one, with higher titers than those reported for most other white rot fungi studied up to date. The effect of copper on in vitro production of extracellular ligninolytic activities was studied. CuSO(4)·5H(2)O concentrations from 1.

[Effect of cocultivating fungal species on the degradation of lignocellulose residues].

The degradation potential of Phanerochaete sordida, Trametes trogii, Coprinus truncorum and Paecilomyces sp. upon yard wastes was evaluated. The species had been inoculated individually or in pairs formed by P.

[Degradation of anthraquinone blue by Trametes trogii].

The ability of the white rot fungus Trametes trogii BAFC 463 (high producer of ligninolytic enzymes, especially laccase and manganese peroxidase) to degrade the dye anthraquinone blue, refractory to bacterial attack, was evaluated. Both tropho- and idiophasic T. trogii cultures in synthetic medium (glucose/asparagine) and complex medium (malt extract/glucose) were able to transform up to 88% dye in 4 hours.

[Degradation of plant waste by Coprinus truncorum using 2 culture methods].

Degradation of yard wastes by Coprinus truncorum growing in a vertical aereated bioreactor or in flasks was studied. There was a constant decay of reducing sugars in the medium that avoided their accumulation and their possible repression of degradative enzymes. Endoxylanase activity at first showed a similar pattern in both culture conditions, with maximal activity on the 12th day, but flasks maintained a high activity thereafter.

Cellulose and xylan degrading enzymes in Thecotheus pelletieri.

The ability to produce cellulose and xylan degrading enzymes by different strains of Thecotheus pelletieri, in liquid synthetic media with cellulose and xylan as inducers, was compared. All the strains tested were able to grow and produce cellulases and xylanases, being the strain BAFC 2077 the best producer. Several cultural conditions were analysed in order to optimise enzyme production by strain 2077.

[Enzymes of white rot fungi involved in lignin degradation].

The presence of oxidases and peroxidases was tested qualitatively in 12 strains of white rot Basidiomycetes. Plate tests with gallic acid, tannic acid, guayacol, Poly R-478 and Azure B were used. Fomes sclerodermeus, Phlebia sp.

[Influence of culture conditions on ligninolytic activity of Stereum hirsutum].

Stereum hirsutum BAFC 2234 was tested for growth kinetics and ligninolytic enzyme production. The strain showed weak coincidences with widely studied organisms (Phanerochaete chrysosporium, Pleurotus ostreatus) when the response to nitrogen sources was assayed. This could be interpreted as a different regulation to nitrogen metabolism for S.

Influence of temperature and pH on cellulase activity and stability in Nectria catalinensis.

The influence of temperature and pH on the activity and stability of the cellulase system (endoglucanase, exoglucanase and cellobiase) was investigated in Nectria catalinensis. Optimal temperature for the activity of the cellulase system ranged from 50 to 55 degrees C, with an optimum for stability between 23 degrees C and 37 degrees C after a 72 h incubation period. For the different enzymes, maximal activity was registered between pH 4.

[Comparative analysis of isoenzyme patterns of beta-1,4 endoglucanase in species of Saccobolus genus (Ascobolaceae-Pezizales)].

Growth and beta-1, 4 endoglucanase production of six species of Saccobolus were determined. Twenty nine strains of thirteen geographical isolates were tested, using culture medium with crystalline cellulose as carbon source. All species showed good growth and enzyme activity.