Removal of dyes by immobilization of Trametes versicolor in a solid-state micro-fermentation system.

A novel bioreactor system (low cost and easily scaled-up) is presented for dye decolorization applying filamentous fungi. In this two-phase bioreactor, dyes were decolorized at 28°C in a first phase by immobilized fungi in spherical cartridges prepared with a high-density plastic polyethylene mesh and filled with wheat bran as substrate for growth. In a second phase the capacity of the ligninolytic enzymes (laccase and Mn-peroxidase) present in the extracellular extracts from the solid residues was exploited for decolorization at 50°C. Each sphere behaved as a small-scale bioreactor for cell-culture. This system allowed the decoupling of growth (sterile condition) and decolorization (non-sterile condition) stages. The ability to decolorize the azo dye xylidine and the triphenylmethane Malachite Green by two Argentinean strains of Trametes versicolor was evaluated. The highest decolorization rates were displayed by T. versicolor BAFC 2234. When both dyes were applied together in the bioreactor, after a first phase (100min) 73.5% of Malachite Green and 40% of xylidine decolorization was attained, while at the end of the second phase (240min) a 97% and 52% decolorization was observed. Laccase activity was detected in the decolorized solution, but no Mn-peroxidase activity. The easy change of the cartridges allows the continuous use of the bioreactor in the non-sterile decolorization of dye-containing effluents.

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. Optimal conditions for PG extraction were: one time extraction with Na2SO4 as solvent with 10 min. of agitation. In a scale-up system, PG activity per gram of dry substrate decreased about 60% compared with the activity obtained in an Erlenmeyer flask; however, high total PG activity was obtained.

Extraction and characterization of polygalacturonase of Fomes sclerodermeus produced by solid-state fermentation / Extracción y caracterización de poligaracturonasa de Fomes sclerodermeus producida por fermentación en estado sólido

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 °C and had optimum activity at pH 5 and 50 °C. Optimal conditions for PG extraction were: one time extraction with Na2SO4 as solvent with 10 min. of agitation. In a scale-up system, PG activity per gram of dry substrate decreased about 60% compared with the activity obtained in an Erlenmeyer flask; however, high total PG activity was obtained.

Se estudió la producción de poligalacturonasa (PG) por Fomes sclerodermeus usando técnicas de fermentación en estado sólido. La actividad PG máxima (26 U/g ps) fue observada entre los días 11 y 13. La actividad PG en los extractos crudos fue más estable a pH 5-6 y 30 °C, con una actividad óptima a pH 5 y a 50 °C. Las condiciones óptimas para la extracción de PG se lograron con una única extracción empleando Na2SO4 como solvente, con 10 minutos de agitación. En el escalado del sistema, la actividad PG por gramo de peso seco de sustrato disminuyó cerca de 60% comparada con la obtenida en frascos Erlenmeyer, pero la actividad total fue mayor.

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. During the first phase using the same culture in the bioreactor, five consecutive charges were made, each with 75 ml of 100 microM MG solution, at 28 degrees C. Each cycle ended when MG solution reached a decolorization of 50%, at this time the bioreactor was discharged to a stainless steel coil at 50 degrees C, initiating the second phase of decolorization. Time required in order to reach 50% decolorization during the first phase varied between 25 and 65 min, with an average retention time of 48 min. The second stage had a retention time of 120 min. Residual MG after this phase varied from 0% to 6.3%. The role of laccase and Mn-peroxidase in MG decolorization is discussed. Toxicity of MG solutions before and after decolorization treatments was assayed using Lumbriculus variegatus as test organism.

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. A 38% total dry-weight loss of the substrate was measured after 28 days of cultivation. Differential hydrolysis of the substrate revealed that cellulose was more extensively degraded than lignin. In the 28-day incubation period, the losses of cellulose and lignin were 38 and 15%, respectively. No lignin peroxidase activity was found in any of the media tested. The maximum manganese-dependent peroxidase activity recorded was 6.3 U g(-1) at 14 days, while the maximum laccase activity was 270 U g(-1) at 28 days post-inoculation. Addition of commonly used inducers such as copper or manganese did not produce a further increase in the enzyme activities, nor did addition of glucose, asparagine, or malt extract.

[Degradation of pine needles by Stereum hirsutum]. / Degradación de hojas de pino por 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. All treatments showed substrate degradation. The addition of a nitrogen source raised enzymatic activities measured but not the degree of degradation. Grain addition resulted in higher biomass, enzyme activities, sugar accumulation and degradation of the substrate. Fungal biomass estimated as N-acetyl glucosamine allowed calculation of the actual degradation of the substrate, that reached 19% at 28 d of culture without additions and 44% at 14 d in pine-needles with grain.

Degradación de hojas de pino por Stereum hirsutum. / [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. All treatments showed substrate degradation. The addition of a nitrogen source raised enzymatic activities measured but not the degree of degradation. Grain addition resulted in higher biomass, enzyme activities, sugar accumulation and degradation of the substrate. Fungal biomass estimated as N-acetyl glucosamine allowed calculation of the actual degradation of the substrate, that reached 19

at 28 d of culture without additions and 44

at 14 d in pine-needles with grain.

Degradación de hojas de pino por Stereum hirsutum / [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. All treatments showed substrate degradation. The addition of a nitrogen source raised enzymatic activities measured but not the degree of degradation. Grain addition resulted in higher biomass, enzyme activities, sugar accumulation and degradation of the substrate. Fungal biomass estimated as N-acetyl glucosamine allowed calculation of the actual degradation of the substrate, that reached 19

at 28 d of culture without additions and 44

at 14 d in pine-needles with grain.

[Effect of cocultivating fungal species on the degradation of lignocellulose residues]. / Efecto del cocultivo de especies fúngicas sobre la degradación de residuos lignocelulósicos.

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. sordida and Paecilomyces sp., T. trogii and Paecilomyces sp., and C. truncorum and Paecilomyces sp. The highest level of endoxilanase activity was produced by P. sordida growing alone, during day 21 (1.09 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, the detected activity did not overcome 0.27 U/g of dry material during the whole experiment. T. trogii showed maximum activity on day 14 (0.78 U/g of dry material), but in T. trogii and Paecilomyces sp. cultures, the values increased until day 21 (1.07 U/g of dry material). P. sordida endocellulase activity reached its maximum on day 28 (0.08 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, this activity increased during the whole experiment (0.04 U/g of dry material). The major weight loss was found in P. sordida (27.6%). The possible beneficial effect of co-culture in yard wastes biodegradation is discussed.

Efecto del cocultivo de especies fúngicas sobre la degradación de residuos lignocelulósicos. / [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. sordida and Paecilomyces sp., T. trogii and Paecilomyces sp., and C. truncorum and Paecilomyces sp. The highest level of endoxilanase activity was produced by P. sordida growing alone, during day 21 (1.09 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, the detected activity did not overcome 0.27 U/g of dry material during the whole experiment. T. trogii showed maximum activity on day 14 (0.78 U/g of dry material), but in T. trogii and Paecilomyces sp. cultures, the values increased until day 21 (1.07 U/g of dry material). P. sordida endocellulase activity reached its maximum on day 28 (0.08 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, this activity increased during the whole experiment (0.04 U/g of dry material). The major weight loss was found in P. sordida (27.6

). The possible beneficial effect of co-culture in yard wastes biodegradation is discussed.

Efecto del cocultivo de especies fúngicas sobre la degradación de residuos lignocelulósicos / [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. sordida and Paecilomyces sp., T. trogii and Paecilomyces sp., and C. truncorum and Paecilomyces sp. The highest level of endoxilanase activity was produced by P. sordida growing alone, during day 21 (1.09 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, the detected activity did not overcome 0.27 U/g of dry material during the whole experiment. T. trogii showed maximum activity on day 14 (0.78 U/g of dry material), but in T. trogii and Paecilomyces sp. cultures, the values increased until day 21 (1.07 U/g of dry material). P. sordida endocellulase activity reached its maximum on day 28 (0.08 U/g of dry material), but in P. sordida and Paecilomyces sp. cultures, this activity increased during the whole experiment (0.04 U/g of dry material). The major weight loss was found in P. sordida (27.6

). The possible beneficial effect of co-culture in yard wastes biodegradation is discussed.

[Degradation of plant waste by Coprinus truncorum using 2 culture methods]. / Degradación de residuos vegetales por Coprinus truncorum usando dos métodos de cultivo.

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. Flasks also showed a higher endoglucanase activity with a peak on the 18th day, whereas the maximal value in the bioreactor was reached on the 26th day. No Mn-peroxidase and only low values of laccase activity were found. The measurements of pH and soluble proteins during the incubation period were suitable indicators of the degradation process by C. truncorum.

Degradación de residuos vegetales por Coprinus truncorum usando dos métodos de cultivo / 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. Flasks also showed a higher endoglucanase activity with a peak on the 18th day, whereas the maximal value in the bioreactor was reached on the 26th day. No Mn-peroxidase and only low values of laccase activity were found. The measurements of pH and soluble proteins during the incubation period were suitable indicators of the degradation process by C. truncorum.

Degradación de residuos vegetales por Coprinus truncorum usando dos métodos de cultivo / 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. Flasks also showed a higher endoglucanase activity with a peak on the 18th day, whereas the maximal value in the bioreactor was reached on the 26th day. No Mn-peroxidase and only low values of laccase activity were found. The measurements of pH and soluble proteins during the incubation period were suitable indicators of the degradation process by C. truncorum.(AU)

Degradación de residuos vegetales por Coprinus truncorum usando dos métodos de cultivo. / [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. Flasks also showed a higher endoglucanase activity with a peak on the 18th day, whereas the maximal value in the bioreactor was reached on the 26th day. No Mn-peroxidase and only low values of laccase activity were found. The measurements of pH and soluble proteins during the incubation period were suitable indicators of the degradation process by C. truncorum.

Interacción entre hongos coprófilos y su efecto en la degradación de su sustrato natural / Interaction between coprophilous fungi and its impact on its natural substrate degradation

Six species of coprophilous fungi were isolated from cow dung. Each species, or a combination of two or more, were inoculated on dung and their capacity of degradation of the substrate was measured as dry weight loss, endoglucanase activity and loss of cellulose. Degradation of CMC agar medium was also established. As a result of their interespecific relationship, a minor degradative capacity was observed when more than one species were cultured except for one combination.

Interacción entre hongos coprófilos y su efecto en la degradación de su sustrato natural / Interaction between coprophilous fungi and its impact on its natural substrate degradation

Six species of coprophilous fungi were isolated from cow dung. Each species, or a combination of two or more, were inoculated on dung and their capacity of degradation of the substrate was measured as dry weight loss, endoglucanase activity and loss of cellulose. Degradation of CMC agar medium was also established. As a result of their interespecific relationship, a minor degradative capacity was observed when more than one species were cultured except for one combination.(AU)

[Effect of calcium and light on the development of Iodophanus carneus]. / Efecto del Ca2+ y de la luz sobre el desarrollo de Iodophanus carneus.

Ca2+ affects the mycelial morphological characteristics in I. carneus, modulating the development and conditioning the sexual differentiation. In Ca2+ 0 mM there was an interaction with light and development, in darkness the colonies did not reach the edge of Petri dishes and spiral growth was observed. In darkness the number of hyphae/mm was greater than those grown in light, except in Ca2+ 1 mM, at 28 mm of inoculum, and Ca2+ 2 mM, at 16 and 28 mm, where the number of hyphae/mm was greater. In cords and apothecial number and location a similar behavior was observed, evidencing a direct relation between these, Ca2+ concentration and light.

Efecto del Ca2+ y de la luz sobre el desarrollo de Iodophanus carneus / Effect of calcium and light on the development of Iodophanus carneus

Ca2+ affects the mycelial morphological characteristics in I. carneus, modulating the development and conditioning the sexual differentiation. In Ca2+ 0 mM there was an interaction with light and development, in darkness the colonies did not reach the edge of Petri dishes and spiral growth was observed. In darkness the number of hyphae/mm was greater than those grown in light, except in Ca2+ 1 mM, at 28 mm of inoculum, and Ca2+ 2 mM, at 16 and 28 mm, where the number of hyphae/mm was greater. In cords and apothecial number and location a similar behavior was observed, evidencing a direct relation between these, Ca2+ concentration and light.