Contribuição ao estudo do ascomiceto chrysonilia sitophila : biodegradação de madeira e seus componentes

AUTOR(ES)
DATA DE PUBLICAÇÃO

1991

RESUMO

Biodegradation of wood and its components by the Ascomycete Chrysonilia sitophila were studied. Optimal growth conditions at pH 6,0, 28°C and nitrogen concentration 50 mEq N/l were observed. Growth in the constitutive nitrogen level and a negligible change in the biotin and tartrate ions presence were found. Nitrogen as either NO3or NH4 was indistinctly assimilated. Semi-solid and agitated cultures induced better growth than stationary cultures. The mycelial chemical composition shows protein (39,2%), carbohydrate (29,3%), ether extract (12,1%), fiber (5,6%), ash (3,3%) and nucleic acids (3,3%) levels similar to some microorganisms used in the single cell protein production. Proteins showed aminoacid levels similar to FAO-WHO requirements. Selective lignin degradation during wood decay was studied. Maximal delignification (18%) after 15 days of biodegradation in a 10 mEq N/l and 1,0% glugose suplemented medium was obtained. Mechanism of lignin biodegradation during wood decay by this Ascomycete was studied. Characteristic reactions of Ca-Cb cleavage, carboxylic acid and new saturated carbons formation in the side chain of lignin and oxidative cleavage of aromatic rings were observed in heavily degraded lignins, as demonstrated to typical degradation caused by white-rot fungi.

ASSUNTO(S)

madeira - biodegradação quimica organica

ACESSO AO ARTIGO

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