Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/19/1998
Publication Date: N/A
Citation: Interpretive Summary: Fungi have the ability to grow on difficult materials. In so doing, they offer the potential to upgrade many agricultural crops to materials with increased value and usefulness in more environmentally friendly methods than those currently used. However, factors which stimulate or retard growth and activity of these fungi are poorly understood and require elucidation to gain their maximum potential. Scientists at the University of Georgia and ARS collaborated in a study of the effect of various compounds found naturally in agricultural crops. Aromatic compounds most stimulatory to growth and enzyme production were identified and the amounts most important were determined. Results are important in establishing fundamental data for methods to maximize the activity of these fungi to degrade difficult materials to serve in upgrading animal feeds, reducing pollutants, clarifying effluent water from industry.
Technical Abstract: Seven benzoic acid, ten cinnamic acid, and five benzaldehyde derivatives were tested for their effect on the growth and production of laccase and manganese peroxidase by Ceriporiopsis subvermispora FP-90031-sp and Cyathus stercoreus ATTC 36910. Derivatives tested included phenolic compounds and their corresponding unsubstituted and O-methylated derivatives. Benzaldehyde derivatives were more toxic to both fungi than the corresponding benzoic and cinnamic acid derivatives. Fungal growth was generally increased at a low concentration of 1 mM while higher concentrations of 5 to 10 mM mostly resulted in less or no growth. In general, monomethoxylated compounds were more toxic than compounds with an additional methoxyl group. C. stercoreus was more sensitive than C. subvermispora to most of the compounds tested and thus showed poorer growth. However, C. stercoreus produced higher concentrations of manganese eperoxidase than C. subvermispora for all the compounds tested, whereas lactase activity was higher in C. subvermispora for most of the compounds tested. Di- and tri-methoxylated compounds induced more laccase and manganese peroxidase activities than the corresponding hydroxylated derivatives. Growth response and enzyme production to the added compounds were generally not related and were rather specific for individual derivatives and their side chain substituents.