1H-NMR Metabolomic Study of the Mushroom Pleurotus djamor for the Identification of Nematocidal Compounds.

Due to the increasing populations of anthelmintic-resistant gastrointestinal nematodes and as a consequence of the adverse effects of synthetic drugs, this study focuses on the search for secondary metabolites with nematocidal activity from the edible mushroom Pleurotus djamor using The proton nuclear magnetic resonance (1H-NMR) metabolomics. The highest activity was shown by the ethyl acetate fractions of mycelium (EC50 290.8 µg/mL) and basidiomes (EC50 282.7 µg/mL). Principal component analysis (PCA) and hierarchical data analysis (HCA) of the 1H-NMR metabolic profiles data showed that the ethanolic extracts, the ethyl acetate, butanol, and water fractions from mycelium have different metabolic profiles than those from basidiomes, while low polarity (hexane) fractions from both stages of fungal development show similar profiles. Orthogonal partial least squares discriminant analysis (OPLS-DA) allowed the identification of signals in the 1H-NMR metabolic profile associated with nematocidal activity. The signals yielded via OPLS-DA and bidimensional NMR analysis allowed the identification of uracil as a component in the ethyl acetate fraction from basidiomes, with an EC50 of 237.7 µg/mL. The results obtained showed that chemometric analyses of the 1H-NMR metabolic profiles represent a viable strategy for the identification of bioactive compounds from samples with complex chemical profiles.

Degradation activity of fungal communities on avocado peel (Persea americana Mill.) in a solid-state process: mycobiota successions and trophic guild shifts.

To explore the capability of soil mycobiota to degrade avocado peel waste and identify relevant successions and trophic guild shifts, fungal communities from three environments with different land uses were evaluated in a solid-state process. Soil samples used as inoculum were collected from a pristine mature tropical forest, a traditionally managed Mayan land, and an intensively managed monospecific avocado plantation. Soil-substrate mixes were evaluated for 52 weeks to evaluate organic matter decay and the carbon-to-nitrogen ratio. Amplicon-based high-throughput sequencing from internally transcribed spacer (ITS) analysis revealed significant differences in fungal communities widely dominated by Fusarium sp. and Clonostachys sp.; however, less represented taxa showed relevant shifts concomitantly with organic matter content drops. Trophic guild assignment revealed different behaviors in fungal communities between treatments over the 52 weeks, suggesting distinct preconditioning of fungal communities in these environments. Overall, the results lead to the identification of promising degradation moments and inoculum sources for further consortia enrichment or bioprospecting efforts.

Nematocidal activity of hydroalcoholic extracts of spent substrate of Pleurotus djamor on L3 larvae of Haemonchus contortus.

The objective of this study was to evaluate and compare the in vitro lethal effect of the hydroalcoholic extract of the spent substrate of Pleurotus djamor ECS-123, obtained at 15 days of colonization (SPS) and at the first (SPS1) and second (SPS2) harvests, against infective larvae L3 of Haemonchus contortus. The in vitro lethal effect was evaluated by the L3 larval mortality test (LM) using six concentrations: 1.25, 2.5, 5, 10, 20, and 40 mg/mL, with ivermectin and thiabendazole (5 mg/mL) as controls. The first harvest extract (SPS1) of strain ECS-123 was subjected to liquid-liquid bipartition, which resulted in two fractions: aqueous (PdAcO) and ethyl acetate (PdAct). The chemical fractionation of PdAct with the highest mortality rate (80.11 %) was carried out with open-column chromatography, giving a total of 13 fractions, which were analyzed by thin-layer chromatography (TLC) and grouped into 5 mixtures (R1;1-3, R2;4-7, R3;8-9, R4;10-11 and R5;12-13). Subsequently, the mixtures were evaluated against H. contortus L3 larvae. Finally, the components of the mixtures with the highest nematocidal effects were evaluated by gas chromatography coupled to mass spectrometry (GC-MS). The data were analyzed with a completely randomized design through ANOVA using the generalized linear model (GLM) with the "R" program. The purification and characterization of R4 and R5 by GC-MS revealed the presence of the following compounds: veratryl alcohol, 4-hydroxy-3,5,5 trimethyl-4-[3-oxo-1-butenyl]-2- cyclohexen-1-one, caffeine and 5,6-dimethoxy-1(3 H) isobenzofuranone. This information allowed for the identification of nematocidal compounds in the degraded substrate of P. djamor, an activity that had not been reported previously.

Nematicidal Effect of Shiitake (Lentinula edodes) Extracts Against Haemonchus contortus.

During the previous decades, the indiscriminate use of anthelmintics for the control of gastrointestinal nematodes has generated anthelmintic resistance in different parts of the world. It is necessary to search for new sustainable control alternatives, such as the use of extracts from plants and edible mushrooms. Therefore, the aim of the present study was to evaluate the nematicidal activity of extracts and fractions of the edible mushroom Lentinula edodes against Haemonchus contortus eggs and infective larvae. The basidiomata of L. edodes ECS-401 were provided by the Tropical Fungi Laboratory of El Colegio de la Frontera Sur and were extracted with ethyl acetate, methanol, and water. Fractionation of the most active extract was carried out by open column chromatography. The bioassays were performed in 96-well microtiter plates using 100 eggs/larvae, a final volume of 100 µL, and different concentrations of extracts/fractions (n = 4). Bioassay readings were taken at 48 h for egg hatching inhibition (EHI) and at 24, 48 and 72 h for larval mortality (LM). The ethyl acetate extract exhibited the highest percentage of EHI (100%). For the LM bioassay, the aqueous extract was the most active (69%), but its fractions did not show larvicidal activity. The chemical profile of the aqueous extract was analyzed by high-performance liquid chromatography, which showed the presence of phenols, flavonoids, and terpenes. L. edodes extracts showed ovicidal and/or larvicidal activity.

In Vitro and In Vivo Nematicide Effect of Extract Fractions of Pleurotus djamor Against Haemonchus contortus.

Sheep haemonchosis is a disease that causes anemia, diarrhea, weight loss, low production, and even death of young animals. This represents a negative economic impact on the livestock sector. For decades, chemicals have been used to control this parasitic disease; however, cases of anthelmintic resistance have increased around the world. For this reason, the search for control alternatives is necessary. Several studies have shown that edible mushrooms of Pleurotus genus have different medicinal properties, including nematicidal activity. In this study, the chromatographic fractionation of the hydroalcoholic extract of fruiting bodies Pleurotus djamor was carried out to identify and isolate the metabolites responsible for nematicidal activity. From the fractionation of the extract, the fraction PdR2 and the subfraction PdB were obtained, which were evaluated against Haemonchus contortus under in vitro conditions. The nematicidal effect of the fraction PdB in gerbils infected artificially with H. contortus was evaluated. Finally, the analysis of the PdB fraction by gas chromatography-mass spectrometry and nuclear magnetic resonance was carried out. The results showed that the PdB had 100% of egg hatching inhibition from 5 mg/mL. Regarding larvicidal activity, it presented >97.2% from 24 h to 20 mg/mL. The in vivo evaluation of the PdB fraction showed a reduction of H. contortus larvae of 92.56%. The compounds present in this fraction were the mixture of allitol and an unidentified terpene in a ratio of 9:1. The PdB fraction is a potential alternative for the control of H. contortus, where allitol and a terpene could be responsible for nematicidal activity.

Chemical Composition of an Anthelmintic Fraction of Pleurotus eryngii against Eggs and Infective Larvae (L3) of Haemonchus contortus.

This study was aimed at evaluating the in vitro effect of the edible mushroom (EM) Pleurotus eryngii against the eggs and larvae (L3) of Haemonchus contortus. The evaluation included acetone (AE) and hydroalcoholic (HA) extracts of the following strains: ECS-1138, ECS-1156, ECS-1255, ECS-1258, ECS-1261, ECS-1282, and ECS-1292. The HA extract of the ECS-1255 strain showed the highest effect on mortality rates of L3 (18.83%) at 20 µg/mL. After subjecting this HA extract to a normal phase chromatography column, five fractions were obtained; fraction F5 (100% MeOH) was the most effective against eggs, with hatching inhibition percentages of 88.77 and 91.87% at 20 and 40 mg/mL, respectively. Gas chromatography-mass spectrometry (GC-MS) subjected this fraction to an acetylation reaction to determine the content of the secondary metabolites. The GC-MS analysis showed that the F5 fraction was composed of trehalose CAS: 6138-23-4, polyols (L-iditol CAS: 488-45-9, galactitol CAS: 608-66-2, D-mannitol CAS: 69-65-8, D-glucitol CAS: 50-70-4, and myoinositol CAS: 87-89-8), adipic acid CAS: 124-04-9, stearic acid CAS: 57-11-4, squalene CAS: 111-02-4, and ß-sitosterol CAS: 83-46-5.

Bacillus subtilis with endocellulase and exocellulase activities isolated in the thermophilic phase from composting with coffee residues / Bacillus subtilis con actividades de endocelulasa y exocelulasa aislado en la fase termofílica del compostaje con residuos de café

The goal of this study was to isolate, select and characterize bacteria with cellulolytic activity from two different coffee residue composting piles, one of which had an internal temperature of 57 -#9702;C and pH 5.5 and the other, a temperature of 61 -#9702;C, and pH 9.3. Culture media were manipulated with carboxymethylcellulose and crystalline cellulose as sole carbon sources. The enzyme activity was assessed by hydrolysis halo formation, reducing sugar production and zymograms. Three out of twenty isolated strains showed higher enzymatic activity and were identified as Bacillus subtilis according to their morphological, physiological, biochemical characteristics and based on the sequence analysis of 16S rDNA regions. The enzymatic extracts of the three selected strains showed exocellulase and endocellulase maximum activity of 0.254 and 0.519 U/ml, respectively; the activity of these enzymes was maintained even in acid pH (4.8) and basic (9.3) and at temperatures of up to 60°C. The enzymatic activities observed in this study are within the highest reported for cellulose produced by bacteria of the genus Bacillus. Endocellulase activity was shown in the zymograms from 24 h until 144 h of incubation. Furthermore, the pH effect on the endocellulase activity is reported for the first time by zymograms. The findings in this study entail the possibility to use these enzymes in the procurement of fermentable substrates for the production of energy from the large amount of residues generated by the coffee agroindustry.

El objetivo de este estudio fue aislar, seleccionary caracterizar bacterias con actividad celulolítica a partir de 2 diferentes pilas de compostaje de residuos de café, una con temperatura interna de 57°C y pH 5,5; la otra con temperatura interna de 61 °C y pH 9,3. Se utilizaron medios de cultivo con carboximetilcelulosa y celulosa cristalina como únicas fuentes de carbono. La actividad enzimàtica fue evaluada por formación de halos de hidrólisis, producción de azúcares reductores y zimogramas. De 20 cepas aisladas, 3 presentaron mayor actividad enzimàtica y fueron identificadas como Bacillus subtilis sobre la base de sus características morfológicas, fisiológicas y bioquímicas y del análisis de las secuencias de la región 16S del ADNr. Los extractos enzimáticos de las 3 cepas seleccionadas presentaron actividad de exocelulasa y de endocelulasa, con máximos de 0,254 y 0,519 U/ml, respectivamente; la actividad de estas enzimas se mantuvo incluso a pH ácido (4,8) o básico (9,3) y a temperaturas de hasta 60 °C. Las actividades enzimáticas halladas en este estudio se ubican dentro de las más altas reportadas para celulasas producidas por bacterias del género Bacillus. En los zimogramas se demostró actividad de endocelulasa desde las 24h hasta las 144h de incubación. Asimismo, se reporta por primera vez el efecto del pH sobre la actividad de endocelulasa observado por zimogramas. Los resultados de este estudio abren la posibilidad de hacer uso de estas enzimas en la obtención de sustratos fermentables para la producción de energía a partir de los residuos generados en grandes cantidades por la agroindustria del café.

The Color of Noise and Weak Stationarity at the NREM to REM Sleep Transition in Mild Cognitive Impaired Subjects.

In Older Adults (OAs), Electroencephalogram (EEG) slowing in frontal lobes and a diminished muscle atonia during Rapid Eye Movement sleep (REM) have each been effective tracers of Mild Cognitive Impairment (MCI), but this relationship remains to be explored by non-linear analysis. Likewise, data provided by EEG, EMG (Electromyogram) and EOG (Electrooculogram)-the three required sleep indicators-during the transition from REM to Non-REM (NREM) sleep have not been related jointly to MCI. Therefore, the main aim of the study was to explore, with results for Detrended Fluctuation Analysis (DFA) and multichannel DFA (mDFA), the Color of Noise (CN) at the NREM to REM transition in OAs with MCI vs. subjects with good performances. The comparisons for the transition from NREM to REM were made for each group at each cerebral area, taking bilateral derivations to evaluate interhemispheric coupling and anteroposterior and posterior networks. In addition, stationarity analysis was carried out to explore if the three markers distinguished between the groups. Neuropsi and the Mini-Mental State Examination (MMSE) were administered, as well as other geriatric tests. One night polysomnography was applied to 6 OAs with MCI (68.1 ± 3) and to 7 subjects without it (CTRL) (64.5 ± 9), and pre-REM and REM epochs were analyzed for each subject. Lower scores for attention, memory and executive funcions and a greater index of arousals during sleep were found for the MCI group. Results confirmed that EOGs constituted significant markers of MCI, increasing the CN for the MCI group in REM sleep. The CN of the EEG from the pre-REM to REM was higher for the MCI group vs. the opposite for the CTRL group at frontotemporal areas. Frontopolar interhemispheric scaling values also followed this trend as well as right anteroposterior networks. EMG Hurst values for both groups were lower than those for EEG and EOG. Stationarity analyses showed differences between stages in frontal areas and right and left EOGs for both groups. These results may demonstrate the breakdown of fractality of areas especially involved in executive functioning and the way weak stationarity analyses may help to distinguish between sleep stages in OAs.

Bacillus subtilis with endocellulase and exocellulase activities isolated in the thermophilic phase from composting with coffee residues.

The goal of this study was to isolate, select and characterize bacteria with cellulolytic activity from two different coffee residue composting piles, one of which had an internal temperature of 57°C and pH 5.5 and the other, a temperature of 61°C, and pH 9.3. Culture media were manipulated with carboxymethylcellulose and crystalline cellulose as sole carbon sources. The enzyme activity was assessed by hydrolysis halo formation, reducing sugar production and zymograms. Three out of twenty isolated strains showed higher enzymatic activity and were identified as Bacillus subtilis according to their morphological, physiological, biochemical characteristics and based on the sequence analysis of 16S rDNA regions. The enzymatic extracts of the three selected strains showed exocellulase and endocellulase maximum activity of 0.254 and 0.519 U/ml, respectively; the activity of these enzymes was maintained even in acid pH (4.8) and basic (9.3) and at temperatures of up to 60°C. The enzymatic activities observed in this study are within the highest reported for cellulose produced by bacteria of the genus Bacillus. Endocellulase activity was shown in the zymograms from 24h until 144h of incubation. Furthermore, the pH effect on the endocellulase activity is reported for the first time by zymograms. The findings in this study entail the possibility to use these enzymes in the procurement of fermentable substrates for the production of energy from the large amount of residues generated by the coffee agroindustry.

Degradation of the herbicide paraquat by macromycetes isolated from southeastern Mexico.

Fifty-four macromycetes, isolated from southeastern Mexico, were used in order to evaluate their capacity for degradation and tolerance to the herbicide paraquat. Ten of these strains were capable of growing in a solid culture medium in the presence of 200 ppm paraquat. Subsequently, assays to evaluate the degradation of the xenobiotic in a liquid medium were carried out. Of the ten strains evaluated, three presented the highest levels of degradation of the compound, which were Trametes pavonia (54.2%), Trametes versicolor (54.1%) and Hypholoma dispersum. They presented the highest overall degradation percentage (70.7%) after 12 days culture. The presence of ligninolytic enzymes in these strains was evaluated. H. dispersum only presented aryl alcohol oxidase activity; however, with the data obtained, it was not possible to conclude whether this specific enzyme is responsible for paraquat degradation. The level of degradation obtained is above the one reported for Pseudomonas putida, one of the few reports on paraquat degradation. This is the first report on the contaminant degradation capacity of H. dispersum.

Self-Heating Pasteurization of Substrates for Culinary-Medicinal Mushrooms Cultivation in Mexico.

The aim of this study was to evaluate a self-heating pasteurization technique in preparing substrates for mushroom production. Seven species were used: Agrocybe aegerita, Auricularia fuscosuccinea, Pleurotus djamor, P. eryngii, P. ostreatus, Lentinula edodes, and Ganoderma lucidum. They were cultivated on grass, corncob, wood shavings, and a mixture thereof. The self-heating technique allowed for pasteurization of 3 of the substrates (grass, corncob, and the mixture). The preheating chamber comprised a drawer placed under the pasteurization crate. With this chamber, it was possible to increase inlet air temperatures by 4--5°C. The evaluated mushroom species responded in different ways to the pasteurization process. P. ostreatus (control) and P. djamor produced basidiomes when cultivated in all pasteurization substrates. A. aegerita and P. eryngii fruited only on corncob and the mixture, whereas A. fuscosuccinea fruited only on the pasteurized corncob. G. lucidum and L. edodes did not fructify on the pasteurized substrates.

Agaricus bisporus production on substrates pasteurized by self-heating.

The aim of this work was to determine if the self-heating pasteurization procedure is technically applicable to the cultivation of Agaricus bisporus. Firstly the substrates alone (corncob, Pangola grass and a mixture of both ingredients with wood shavings) were tested. Two supplementation trials were then undertaken using soybean, wheat bran, sheep manure, sesame seed, black bean and chia. Highest production values (BE = 176.3% and Y = 26.6 kg/m2) were obtained using a 9% supplement, with a formula consisting of 25% each of soybean, black bean, wheat bran and chia, added at spawning and at casing. These results were comparable to those obtained with the Phase II compost traditionally used for A. bisporus cultivation.

Producción de enzimas ligninolíticas durante la degradación del herbicida paraquat por hongos de la pudrición blanca / Ligninolytic enzyme production by white rot fungi during paraquat (herbicide) degradation

El paraquat es un herbicida utilizado ampliamente en la agricultura. Debido a su gran distribución y uso inadecuado, representa un problema grave de contaminación del suelo y el agua. Se ha encontrado que los hongos de la podredumbre blanca son capaces de degradar compuestos contaminantes que poseen estructuras similares a la lignina, como es el caso del paraquat. En el presente trabajo se evaluó la degradación de este herbicida y su efecto en la producción de enzimas ligninolíticas por parte de algunos hongos de la podredumbre blanca aislados del sur de México. Seis cepas fúngicas mostraron tolerancia al herbicida durante el cultivo en medio sólido. Tres de las 6 cepas evaluadas, correspondientes a las especies Polyporus tricholoma, Cilindrobasidium laeve y Deconica citrispora, mostraron niveles de degradación del 32, el 26 y el 47%, en ese orden, a los 12 días de cultivo en presencia del xenobiótico. Se detectó un incremento en las actividades de las enzimas lacasa y Mn-peroxidasa en las cepas que presentaron el mayor porcentaje de degradación, probablemente asociado a la disminución del herbicida. Adicionalmente, se realizaron ensayos con extractos enzimáticos procedentes del medio de cultivo extracelular de las 2 cepas que presentaron mayor degradación. Después de 24 h de incubación, se obtuvo una degradación del 49% del paraquat inicial con los extractos de D. citrispora. Los resultados obtenidos indican que la degradación del herbicida estaría asociada a la presencia de enzimas extracelulares en los hongos de la podredumbre blanca. En este trabajo se muestran las primeras evidencias del potencial de biodegradación de diferentes especies de hongos de la pudrición blanca.

Paraquat is a widely used herbicide in agriculture. Its inappropriate use and wide distribution represents a serious pollution problem for soil and water. White rot fungi are capable of degrading pollutants having a similar structure to that of lignin, such as paraquat. This study evaluated the degradation effect of paraquat on the production of ligninolytic enzymes by white rot fungi isolated from the South of Mexico. Six fungal strains showed tolerance to the herbicide in solid culture. Three of the six evaluated strains showed levels of degradation of 32, 26 and 47% (Polyporus tricholoma, Cilindrobasidium laeve and Deconica citrispora, respectively) after twelve days of cultivation in the presence of the xenobiotic. An increase in laccase and manganese peroxidase (MnP) activities was detected in the strains showing the highest percentage of degradation. Experiments were done with enzyme extracts from the extracellular medium with the two strains showing more degradation potential and enzyme production. After 24 hours of incubation, a degradation of 49% of the initial paraquat concentration was observed for D. citrispora. These results suggest that paraquat degradation can be attributed to the presence of extracellular enzymes from white rot fungi. In this work the first evidence of the biodegradation potential of D. citrispora and Cilindrobasidium leave is shown.

[Ligninolytic enzyme production by white rot fungi during paraquat (herbicide) degradation]. / Producción de enzimas ligninolíticas durante la degradación del herbicida paraquat por hongos de la pudrición blanca.

Paraquat is a widely used herbicide in agriculture. Its inappropriate use and wide distribution represents a serious pollution problem for soil and water. White rot fungi are capable of degrading pollutants having a similar structure to that of lignin, such as paraquat. This study evaluated the degradation effect of paraquat on the production of ligninolytic enzymes by white rot fungi isolated from the South of Mexico. Six fungal strains showed tolerance to the herbicide in solid culture. Three of the six evaluated strains showed levels of degradation of 32, 26 and 47% (Polyporus tricholoma, Cilindrobasidium laeve and Deconica citrispora, respectively) after twelve days of cultivation in the presence of the xenobiotic. An increase in laccase and manganese peroxidase (MnP) activities was detected in the strains showing the highest percentage of degradation. Experiments were done with enzyme extracts from the extracellular medium with the two strains showing more degradation potential and enzyme production. After 24hours of incubation, a degradation of 49% of the initial paraquat concentration was observed for D. citrispora. These results suggest that paraquat degradation can be attributed to the presence of extracellular enzymes from white rot fungi. In this work the first evidence of the biodegradation potential of D. citrispora and Cilindrobasidium leave is shown.

Can consumption of antioxidant rich mushrooms extend longevity?: antioxidant activity of Pleurotus spp. and its effects on Mexican fruit flies' (Anastrepha ludens) longevity.

The variability of antioxidant capacity of 14 strains of the edible oyster mushroom Pleurotus spp. was determined, and the effect of selected mushroom supplements on the longevity of the Mexican fruit fly, Anastrepha ludens, was evaluated. The antioxidant capacity of the fruiting bodies was determined by three different methods, measuring the free radical scavenging activity of methanolic extracts, the OH radical scavenging capacity, and the total phenol content. The inhibition percentage of the DPPH radical varied between 32.6 and 85.7% and total phenols varied between 30.6 and 143.3 mg/g. The strains with the highest (Pleurotus djamor ECS-0142) and lowest (Pleurotus ostreatus ECS-1123) antioxidant capacity were selected to study their effect on the survival, life expectancy, and mortality of the Mexican fruit fly A. ludens. The results demonstrated differing responses between male and female flies. High concentrations of mushrooms (5 and 20%) in the diet resulted in a decrease in life expectancy. However, flies on the diet with 1% P. djamor ECS-0142 showed slightly but significantly greater survival than those on the control diet. The possible adverse effect of protein content in mushroom extracts is discussed.

Hongos comestibles y medicinales en Iberoamérica: investigación y desarrollo en un entorno multicultural / Edible and medicinal fungi in Ibero-America: research and development in a multicultural environment

Los macromicetos u hongos macroscópicos conforman un grupo especial del Reino de los Hongos que adquiere cada día mayor relevancia. En efecto, existe en el mundo un claro interés por el conocimiento y la domesticación de estos organismos, toda vez que se descubren cada día mayores posibilidades de beneficio para la humanidad a partir de ellos. Si de la totalidad de especies de hongos estimadas sobre la tierra, una cuarta parte pertenecen a este grupo (lo que hace una estimación de alrededor de 400 mil especies), es evidente que aún queda muchísimo por conocer. Los avances actuales de la humanidad han permitido cultivar sólo un centenar. Es claro entonces, que con 0.025% de estos organismos domesticados ­mas no todos ellos bien conocidos- la rama de la micotecnología dedicada al cultivo de los macromicetos aún no inicia su expansión, mas bien se encuentra en fase de latencia o incubación y se esperaría que abundantes descubrimientos y grandes desarrollos y beneficios se concretaran en un futuro no muy lejano, en base a investigación y se difundieran mediante capacitación, transferencia y apropiación del conocimiento. Los temas tratados durante el taller superaron el planteamiento inicial ya que, además de tratar estrictamente el tema de cultivo de hongos comestibles, se abordaron temas como la situación y el potencial de los hongos silvestres. También se trataron diferentes aspectos de varios hongos de interés medicinal y funcional, y aún temas sobre manejo postcosecha de los hongos, entre otros. Estos tópicos no estaban contemplados inicialmente, pero resultaron indispensables para conformar una mejor perspectiva sobre la situación que guarda el cultivo y el aprovechamiento de los macromicetos en Iberoamérica.

Use of spent substrate after Pleurotus pulmonarius cultivation for the treatment of chlorothalonil containing wastewater.

Lignocellulosic materials are used as substrate for the cultivation of the edible mushroom Pleurotus pulmonarius. After two or three flushes of mushrooms, the spent substrate is discarded although it still has an important enzymatic activity that can be used for several purposes. In this study, we sought to determine the technical feasibility of using spent substrate from P. pulmonarius to degrade chlorothalonil. Reaction mixture was prepared with 6 ml of pesticide aqueous solution (2 mg active ingredient/l) and 3 ml of enzymatic extract obtained from spent P. pulmonarius substrate. The enzymatic reaction (27 °C, pH 7.4) was conducted for 1 h with sampling at 15 min intervals. The effect of storage time and temperature (freezing or refrigerating) of spent substrate and enzymatic extract, respectively, on the activity over chlorothalonil was determined. Freshly obtained spent substrate extract was able to reduce 100% of the initial concentration of chlorothalonil (2 mg/l) after 45 min of reaction. Storage time had a negative effect on the stability of the enzymatic activity: with spent substrate stored for a week, chlorothalonil concentration was reduced in 49.5% after 1 h reaction and with substrate stored for two and three weeks, the degradation efficiency decreased to 9.15% and 0%, respectively. Cooling and freezing the spent substrate extract also had a negative effect on chlorothalonil degradation.

Scytalidium thermophilum-colonized grain, corncobs and chopped wheat straw substrates for the production of Agaricus bisporus.

We examined the possibility of cultivating Agaricus bisporus (Ab) on various grains and agricultural by-products, with the objective of improving yield capacity of substrate pre-colonized by Scytalidium thermophilum (St). Radial growth rate (RGR) of St at 45 degrees C ranged from no growth on sterile wheat grain to 14.9 mm/d on whole oats. The linear extension rate (LER) of Ab, grown on St-colonized substrate (4 days at 45 degrees C), ranged from a low of 2.7 mm/d on 100% corncobs to 4.7 mm/d on a 50/50 mixture of ground corncobs/millet grain. Several other substrates containing wheat straw+ground corncobs+boiled millet and pre-colonized by St (4 days at 42+/-3 degrees C), were evaluated for production of Ab. The biological efficiency (BE) of production increased linearly with the addition of millet to the formula. However, substrates with millet levels 84% often were contaminated before mushroom harvest. Maximum BE (99%) and yield (21.6 kg/m(2)) were obtained on St-colonized wheat straw+2% hydrated lime supplemented with 9% commercial supplement added both at spawning and at casing.

Pangola grass colonized with Scytalidium thermophilum for production of Agaricus bisporus.

This work had the dual objective of selecting a substrate for rapid mycelial growth of Scytalidium thermophilum and then comparing the growth and production of a brown variety of Agaricus bisporus on substrate non-colonized and colonized with S. thermophilum. Mycelial growth of S. thermophilum at 45 degrees C was significantly greater on potato dextrose yeast extract agar (0.58 mm/h) as compared to malt extract glucose agar (0.24 mm/h) and yeast extract glucose agar (0.44 mm/h). On cereal grain, S. thermophilum grew significantly faster on rice (0.31 mm/h) compared to sorghum (0.22 mm/h) and millet (0.18 mm/h). It also grew faster on Pangola grass (0.49 mm/h) compared to corncobs (0.30 mm/h) and sawdust (0.18 mm/h). Colonization of Pangola grass with S. thermophilum was influenced by the addition of calcium salts in the form of gypsum, hydrated lime and ground limestone. For production of A. bisporus, biological efficiency (BE) on pasteurized Pangola grass pre-colonized by S. thermophilum for 4 days at 45 degrees C was more than twice (26.4%) that on grass non-colonized by S. thermophilum (11.0%). The addition of 2% hydrated lime to Pangola grass prior to colonization by S. thermophilum resulted in an additional doubling of BE of mushroom production (48.1%). These results show the possibility of developing a non-composted substrate method for producing A. bisporus without autoclaving the substrate.

A simple procedure for preparing substrate for Pleurotus ostreatus cultivation.

The use of wooden crates for composting a mixture of 70% grass, (Digitaria decumbens), and 30% coffee pulp, combined with 2% Ca(OH)(2), was studied as a method for preparing substrate for the cultivation of Pleurotus ostreatus. Crate composting considerably modified the temperature pattern of the substrate in process, as compared to pile composting, where lower temperatures and less homogeneous distributions were observed. Biological efficiencies varied between 59.79% and 93% in the two harvests. Based on statistical analysis significant differences were observed between the treatments, composting times and in the interactions between these two factors. We concluded that it is possible to produce P. ostreatus on a lignocellulosic, non-composted, non-pasteurized substrate with an initial pH of 8.7, and that composting for two to three days improves the biological efficiency.