RESUMO
The effects of light and quantity of spawn on the sporophore and sclerotial yields of Pleurotus tuber-regium, cultivated on cotton wastes, rice straw, cocoyam peel, corncob, groundnut shell and sawdusts of Mansonia altissima, Khaya ivorensis and Boscia angustifolia were observed.The organism had sporophore and sclerotial yield values of 36.8 and 27.6 g kg-1 waste, respectively, in cotton waste, at light quantum of 695 lux. There was a highly significant increase in yield of sclerotia (188.0 g kg-1 waste), in total darkness , while malformed fruitbodies (sporophores) were produced in all the substrates under the same condition. Increasing the quantity of spawn from 5 to 30% reduced the period of spawn run from 13 to 6, 15 to 8 and 24 to 17 days, respectively, in P. tuber-regium fruitbodies grown in cotton waste, rice straw and sawdust of B. angustifolia, with yield values of 38.0 and 20.0 g kg-1 waste in cotton waste and rice straw. The optimal spawn levels for sclerotia formation in the two wastes were 10 and 5%, respectively. .The mushroom did not produce sclerotia in corn cob and groundnut shell when exposed to light. However, maximal yield values of 286.8 and 288.4 g kg-1 waste were obtained in both substrates in total darkness.
RESUMO
When Pleurotus tuber-regium was cultivated on cotton waste , rice straw, cocoyam peels and sawdusts of Mansonia altissima, Boscia angustifolia and Khaya ivorensis, the highest crude protein, crude fat and carbohydrate contents in sporophores were 29.4 (M. altissima) , 1.4 (rice straw) and 61.3% (cocoyam peels), respectively. Sporophores produced on rice straw had the greatest energy value and those on B. angustifolia the least i.e. 3147.6 and1709.1 kcal g-1 substrates, respectively. The greatest degradation of the components of the substrates as a result of the cultivation was 62.4 and 71.5% for cellulose and hemicellulose in cotton wastes and 60.2% for lignin in K. ivorensis , with the greatest reduction in energy value of the substrate being 2667.9 kcal g-1 substrate in K. ivorensis. There was no correlation between the extent of the degradation of these components and the yield of of sporophores, while the energy recovery of substrate in the mushroom was highest for cocoyam peels and least for sawdust of B. angustifolia, 3.7 and 0.5%, respectively.
RESUMO
Whole plants of Eichhornia crassipes and Pistia stratiotes were exposed to various concentrations (0, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mM) of 8 heavy metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb and Zn) hydroponically for 21 days. Spectrometric assays for the total activity of catalase, peroxidase, and superoxide dismutase in the leaves were studied. At the end of the experimental period, data referred to metal treated plants were compared to data of untreated ones (control). Heavy metals increased the activity of catalase, peroxidase and superoxide dismutase in both species and there was differential inducement among metals. Overall, Zn had the least inducement of antioxidant enzymes in both species while Hg had the highest inducement. The increase in antioxidant enzymes in relation to the control plants was more in E. crassipes than P. stratiotes. The results showed that E. crassipes tolerated higher metal concentrations in a greater number of metals than P. stratiotes. Rev. Biol. Trop. 55 (3-4): 815-823. Epub 2007 December, 28.
Plantas completas de Eichhornia crassipes y Pistia stratiotes fueron expuestas a varias concentraciones (0, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mM) de metales pesados (Ag, Cd, Cr, Cu, Hg, Ni, Pb and Zn) utilizando hidroponía, por 21 días. Se realizaron análisis espectrométricos en las hojas para determinar la actividad total de la catalasa, peroxidasa y dismutasa superóxida. Al final del periodo experimental, se comparó con plantas no tratadas (control). Los metales pesados incrementan la actividad de la catalasa, peroxidasa y la dismutasa superóxida para ambas especies y hay diferencias entre los metales. El Zn produce el menor estímulo para enzimas antioxidantes en ambas especies; Hg produce el mayor estímulo. El incremento de las enzimas antioxidantes en relación con las plantas control fue mayor en E. crassipes que P. stratiotes. E. crassipes tolera altas concentraciones de metal en un gran número de ellos, mientras que la tolerancia en P. stratiotes es menor.