ABSTRACT
Tolerance of wood decay fungi of the genera Agrocybe, Armillaria, Auricularia, Daedalea, Pleurotus, Trametes to the presence of various amounts of creosote-treated wood (CTW) in the growth medium was compared. In the case of the most tolerant strain, Pleurotus ostreatus SMR 684, extracellular laccase and peroxidase specific activities were monitored during growth in the presence of CTW. Degradation of various creosote-constituting polycyclic aromatic hydrocarbons by this strain was evaluated by GC-MS and the ecotoxicity of treated and untreated CTW was compared by Microtox test.
Subject(s)
Creosote/metabolism , Mycelium/growth & development , Mycelium/metabolism , Wood/metabolism , Wood/microbiology , Creosote/chemistry , Laccase/metabolism , Mycelium/enzymology , Oxidation-Reduction , Peroxidase/metabolism , Pleurotus/enzymology , Pleurotus/growth & development , Pleurotus/metabolism , Polycyclic Aromatic Hydrocarbons/metabolism , Polycyclic Aromatic Hydrocarbons/toxicity , Soil Pollutants/metabolism , Triticum/metabolism , Wood/chemistryABSTRACT
A bioremediation system for creosote-treated wood is proposed, based on the detoxifying capability of Pleurotus ostreatus, a ligninolythic fungus. Non-sterilized chipped contaminated wood was mixed at various ratios with wheat straw on which Pleurotus mycelia was grown. At 1:2 initial ratio contaminated wood:wheat straw, chemical analyses demonstrated an almost complete degradation of creosote oil components after 44 days, also confirmed by a significant reduction of ecotoxicity. Lower ratios, i.e. higher amount of contaminated wood, lower system efficiency, although a better creosote degradation was obtained by a stepped up wood addition.
Subject(s)
Creosote/chemistry , Environmental Restoration and Remediation , Pleurotus/chemistry , Wood/analysis , Algorithms , Animals , Biodegradation, Environmental , Carcinogens/analysis , Daphnia , Gas Chromatography-Mass Spectrometry , Mycelium/chemistry , Mycelium/metabolism , Oxidation-ReductionABSTRACT
Chitinous material was isolated from the mycelium of seven species of Basidiomycetes to evaluate the possibility of using fungal biomass as a source of chitin and chitosan. Such material was characterised for its purity, degree of acetylation and crystallinity. Chitin yields ranged between 8.5 and 19.6% dry weight and the chitosan yield was approximately 1%. The characteristics of the fungal chitins were similar to those of commercial chitin. Chitosans, with a low degree of acetylation, comparable with that of commercial chitosan, were obtained by the chemical deacetylation of fungal chitins.
Subject(s)
Basidiomycota/chemistry , Chitin/chemistry , Acetylation , Spectroscopy, Fourier Transform InfraredABSTRACT
AIMS: The objective of the present study was to determine the optimum conditions for copper (Cu) biosorption by Auricularia polytricha mycelium in view of its immobilization in polyvinyl alcohol (PVA). METHODS AND RESULTS: The adsorption of Cu(II) onto A. polytricha was studied in batch with respect to initial pH, temperature, adsorption time, initial metal ion and biomass concentration. At optimal adsorption conditions, biomass was immobilized in PVA in column and a biosorption capacity of about 90% was obtained. CONCLUSIONS: Auricularia polytricha strain could successfully be used as Cu biosorbent. SIGNIFICANCE AND IMPACT OF THE STUDY: The low cost and simplicity of the technique make it suitable for the detoxification of contaminated effluents before their environmental discharge.
