Effects of heavy metals on some proximate composition of Eichhornia crassipes

Effects of 8 heavy metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb and Zn) on the total chlorophyll, foliar proline, and protein and starch contents of Eichhornia crassipes was investigated. Plantlets were grown in quarter-strength Hoagland's solution and supplemented with 0, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mM of each of the metals for 3 weeks. There was a significant reduction (p≤0.05) in total chlorophyll, protein and starch contents, while foliar proline increased significantly. These effects were however dependent on the nature of the metal, its concentration and duration of exposure. Journal of Applied Sciences and Environmental Management Vol. 10(1) 2006: 83-8

Bioremediation of oil-polluted soil by Lentinus subnudus, a Nigerian white-rot fungus

Inspite of the realization and studies on the use of microorganisms in degrading hydrocarbons there has been very little work on indigenous white-rot fungi in Nigeria, a leading oil – producing country. the ability of Lentinus subnudus to mineralize soil contaminated with various concentrations of crude oil was tested. Organic matter and carbon were higher than the control at all concentrations of crude oil contamination in soils inoculated with L. subnudus for 3 months. Nutrient contents were generally higher after 6 months of incubations except potassium levels which were not significantly different from the control. As for the total petroleum hydrocarbon (tph) in crude – oil contaminated soils; the highest rate of biodegradation was at 20% concentration after 3 months and 40% after 6 months of incubation.Key words: bioremediation, crude oil, total petroleum hydrocarbon oil-polluted soil, Lentinus subnudusAfrican Journal of Biotechnology Vol. 4 (8), pp. 796-79

Cultivation and fruit body production of Lentinus squarrosulus Mont. (Singer) on bark and leaves of fruit trees supplemented with agricultural waste

The mycelia growth of Lentinus squarrosulus culture on the leaves and bark of common fruit trees were investigated. The effect of supplementing these fruit trees with 25% each of rice bran, horse dung, poultry droppings, cow dung, fresh cassava flour and oil palm waste fiber on the mycelia growth of this fungus was also observed. All the substrates supported the growth of the fungus, while supplemented substrates gave higher mycelia growth. The best mycelia growth was recorded on the leaves of Spondias mombin with 8.90 cm length. Among the supplements, rice bran gave the highest mycelia growth of 10.43 cm on S. mombin. Fruiting of the fungus on the logs of the best two substrates commenced after 28 days of inoculation and occurred every four days. The highest yield of fruit bodies and the best biological efficiency was obtained on the log of S. mombin, while the leaf substrates did not fructify even after 35 days of inoculation.Keywords: Lentinus squarrosulus, supplements, fruit body, biological efficiency

Centesimal composition and physical-chemistry analysis of the edible mushroom Lentinus strigosus occurring in the Brazilian Amazon

The centesimal composition and the physical and chemical analyses of Lentinus strigosus, an edible mushroom occurring in the Brazilian Amazon and produced in alternative substrates based on wood and agroindustrial residues, were evaluated. For this purpose, the C, N, pH, soluble solids, water activity, protein, lipids, total fiber, ash, carbohydrate, and energy levels were determined. The substrates were formulated from Simarouba amara Aubl. marupá"), Ochroma piramidale Cav. Ex. Lam. pau-de-balsa") and Anacardium giganteum cajuí") sawdust and Bactris gasipaes Kunth pupunheira") stipe and Saccharum officinarum (sugar cane bagasse). The results indicated that the nutritional composition of L. strigosus varied with the substrate of cultivation; the protein levels found in mushrooms grown in the different substrates (18 –21.5%) varied with the substrate and was considered high; the soluble solids present in the mushrooms could have a relation with complex B hydrosoluble vitamins. L. strigosus could be considered as important food owing to its nutritional characteristics such as high protein content, metabolizable carbohydrates and fibers, and low lipids and calories content.Avaliou-se a composição centesimal e análise físico-química do Lentinus strigosus, um cogumelo comestível de ocorrência na Amazônia brasileira, produzidos em substratos alternativos à base de resíduos madeireiros e agroindustriais. Com este objetivo, determinou-se C, N, pH, sólidos solúveis, atividade de água, proteína, lipídios, fibra total, cinzas, carboidratos e energia. Os substratos foram formulados a partir de serragem de Simarouba amara Aubl. (marupá), Ochroma piramidale Cav. ex. Lam. (pau-de-balsa) e Anacardium giganteum (cajuí); e do estipe de Bactris gasipaes Kunth (pupunheira) e de Saccharum officinarum (cana-de-açúcar). Os resultados demonstraram que: a composição nutricional do L. strigosus variou com o substrato de cultivo; os valores de proteína encontrados nos cogumelos cultivados nos diferentes substratos (18 - 21,5%) variaram de acordo com o substrato, sendo considerados elevados; os sólidos solúveis presentes nos cogumelos podem ter relação com vitaminas hidrossolúveis do complexo B; o L. strigosus pode ser considerado um importante alimento devido suas características nutricionais: alto teor de proteína, carboidratos metabolizáveis e fibras; baixos teores de lipídios e de calorias

Changes in antioxidant enzyme activities in Eichhornia crassipes (Pontederiaceae) and Pistia stratiotes (Araceae) under heavy metal stress

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

Effect of Crude Engine Oil and Aromatic Fractions of Pleurotus Pulmonarius Fries (Quelet)

The ability of two white rot fungi, Pleurotus ostreatus and P. pulmonarius, to degrade crude and used engine oil was examined for six months. In 9 9 4 cm (350 cm3) jam bottles, 100 grams of sterilized soil were weighed and wet with 75% distilled water (w/v). They were then completely mixed with bonny light crude oil and used motor oil at various concentrations (0%, 5%, 10%, 15%, 25%, and 30%), individually. Then, using a sterile cork borer, two agar plugs of a strongly growing P. ostreatus and P. pulmonarius mycelium were inoculated into each bottle. For six months, the bottles were kept at room temperature. After drying, the mycelia-ramified waste was removed from the soil and examined for physicochemical characteristics such total hydrocarbon content (THC), organic matter, carbon, nitrogen, phosphorus, and potassium. After six months, both contaminated and inoculated soils had higher levels of organic carbon, nitrogen, and phosphorus. However, during the experiment period, these soils had a drop in THC, pH, and potassium. In soils contaminated with 20% of crude and engine oils, respectively, P. ostreatus lowered the initial THC to 8% and 9%, which was less than P. pulmonarius. The two white rot fungus may be used in the bioremediation of soils contaminated with old motor oil and bonny light crude

Insecticidal activities of the African yam bean seed lectin on the development of the cowpea beetle and the pod sucking bug

The cowpea beetle, Callosobruchus maculatus, and pod-sucking bug, Clavigralla tomentosicollis, are two of the major insect pests of cowpea in Africa. A lectin was purified from the seeds of the African yam bean (AYB), Sphenostylis stenocarpa, by affinity chromatography on Galactosc-Sepharose 4B. The purified AYB lectin (AYBL) was tested on the two insect pests of cowpea. When C. maculatus larvae were fed on artificial cowpea seed containing 0.2, 2, and 5% (w/w) of dietary lectin, larval mortality ranged from 30 to 88% and delay in number of days to first emer gence from 4-13 days. When AYBL was tested on C. tomentosicollis, nymphal mortalities ranged from 76 to 81% at 1% and 87 to 94% at 2%. From 4 to 8%, no nymph survived up to six days after infestation. The results of these insect bioassays provided a scientific basis for isolating a lectin gene from AYB for the transformation of cowpea

BIODEGRADATION OF AGRO-WASTES BY SOME NIGERIAN WHITE-ROT FUNGI

Three white-rot fungi: Daedalea elegans, Polyporus giganteus, and Lenzites betulina were screened for their lignin degrading abilities on rice straw, maizecob, sawdust of Terminalia superba, and sugarcane bagasse at different time intervals (30, 60, and 90 days). All the fungi demonstrated varying levels of ligninolytic capability with different degrees of lignin degradation in all the fermented substrates. A significant difference (p<0.05) was observed in the mycelia extension of Daedalea elegans grown on the different agro-industrial wastes. D. elegans gave maximum extension of 4.5 cm on sugarcane bagasse. The highest lignin reduction of 92.9% (p<0.05) was recorded in maize cob fermented with Daedalea elegans after 90 days. On the basis of lignocellulosic material degraded, it is concluded that the white-rot fungi offer a better alternative to conventional ways of disposing these waste substances. This paper considers the ability of indigenous white-rot fungi to degrade lignin as a way of using them in effective waste management