Estudo da degradação de polimeros sinteticos de importancia industrial por linhagens fungicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

This work describes the action of basidiomycetes fungi on the degradability of the four main synthetic polymers used in food packaging: polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC) and another synthetic polymer, a polyurethane foam (PU). The microorganisms were grown in the salts liquid medium, pH 6.8, containing 0.1 % of thiamine, with 0.5 % of synthetic polymer as the sole carbon source for 20,30 and 40 days of cultivation. The biodegradability of these plastics was evaluated by monitoring the growth of the lignocellulose-degrading organisms on carbondeficient liquid medium; determination of the molar mass loss of the polymers, of the cellular mass grown on the surface, and microscopic examination at the end of the incubation assays by Scanning Electron Microscopy (SEM), which indicated changes in the integrity of the plastics, particularly in PVC specimens, which suffered very significant mass reductions (about 20 %). The ability of the fungi to produce cellulolytic and ligninolytic enzymes, such as avicelase, xylanase, carboximethilcellulase, manganese peroxidase, lignin peroxidase, alcohol veratryl oxidase and laccase, as well as of biosurfactants was observed, revealing the potential of these organisms in biodegradation processes. The detection of degradation products of the plastics in the culture medium was verified using ultraviolet-visible spectrophotometry, in the wavelength range of 200 to 500 nm, which produced interesting results for PVC with Pleurotus 001. The degradation of the polymers, investigated using viscosimetric methods and Gel Permeation Chromatography (GPC), resulted in viscosity loss on the polymers following incubation with microorganisms and small changes in the molar mass distribution in the polymers tested (PVC and PS). Our results indicated structural alterations in the synthetic polymers due to biodegradation process

ASSUNTO(S)

basidiomicetos fungos biodegradação polimeros

ACESSO AO ARTIGO

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