Fungi biodegradation of vinasse from industrial sugarcane processing / Biodegradação de vinhaça proveniente do processo industrial de cana-de-açúcar por fungos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Vinasse is a residue resulting from the production of alcohol after pulp fermentation and distillation of the wine, ensuing from 10 to 15 liters for each liter of ethanol produced. This high colored effluent is a by-product rich in nutrients, mainly organic matter, having a high pollutant potential when disposed in the environment. Lignolytic fungi can be utilized in the remediation of pollutants, such as vinasse, by the action of peroxidases. Assays for the decolorization of vinasse by three ascomycetes fungi and five basidiomycetes were performed and consequently selecting the fungus Pleurotus sajor-caju CCB 020. The activities of manganese-dependent peroxidases (MnP) and laccases and the quantification of the decolorization after the treatment of the vinasse by P. sajor-caju were evaluated and it was observed that this fungus can be utilized to biodegrade and decolorize the vinasse at a concentration of 100% without the necessity of dilution. P. sajorcaju is an edible fungus with nutritional values determined in the literature. The vinasse trigged the process of oxidative stress in the fungus, fact observed through the elevation of the enzyme activities (superoxide dismutase, catalase and glutathione reductase) associated to mechanisms of detoxifying reactive oxygen species. When compared to the growth in synthetic medium, the tests in submerged vinasse cultivation with P. sajor-caju demonstrated a raise in the biomass production (1,06 g 100 mL-1), and in the enzyme activities such as laccase (varying from 400 to 450 U L-1) reached between the 9th and 10th day of growth and for MnP at the 12th day of cultivation (varying from 60 a 100 U L-1), indicating the participation of these enzymes in the depolymerization of phenolic compounds and melanoidins pigments. In the same treatments were observed reductions of 82,76% in COD, 75% of BOD, 99,17% in the color and 99,73% for the turbidity. After the treatment with the fungus, a reduction in the toxicity was evident through the exposition of Pseudokirchneriella subcapitata, Daphnia magna, Daphnia similis e Hydra attenuata. It was concluded that the system P.sajor caju/vinasse can be utilized as a bioprocess for color removal and degradation of complex molecules. It was observed an improvement in the characteristics and detoxification allowing it to be utilized as reused water, laccase and manganese peroxidase enzymes production and for fungal biomass production with a high nutritional value.

ASSUNTO(S)

enzyme degradation vinhaça ligninolytic fungi oxidative stress bioensaios enzimas fungos biodegrdação bioassays. descolorization extresse oxidativo

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