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In order to utilize phenolic compounds in unused biomass resources, the metabolic pathway of ferulic acid by way of a white-rot fungus, Schizophyllum commune, was investigated. Ferulic acid was immediately degraded, and the formation of 4-vinyl guaiacol was confirmed by GC-MS analysis. The metabolic test of ferulic acid and its degradation products indicated that S. commune converted ferulic acid into 4-vinyl guaiacol by decarboxylation. This was then oxidized to vanillin and vanillic acid. This result indicates that S. commune distinguished ferulic acid from lignins and metabolized it specifically.

The factors that cause weather-induced deterioration of wood surfaces were determined by chemical and spectroscopic analyses. Albizzia (Paraserianthes falcata Becker.) and sugi (Cryptomeria japonica D. Don) were exposed to two temperate conditions of natural weathering with and without rainfall and to accelerated conditions of artificial weathering coupled with ultraviolet (UV) light irradiation and water flashing. Infrared spectroscopic analysis showed that the oxidative reaction of lignin was observed under all conditions of weathering for both wood species. However, a marked decrease in lignin and hemicellulose content were recognized when albizzia woods were exposed to weathering with water. Lignin content in the softwood sugi did not decrease as much as in albizzia even in the presence of water, but the modification of lignin macromolecules was assumed to be accelerated by water, as seen by electron spin resonance spectroscopy. These results showed that the presence of water promotes the weathering deterioration of wood under UV irradiation.

BACKGROUND: For effective saccharification of rice straw we focused on enzyme preparations from wood-rotting fungi that have the ability to degrade cell wall polysaccharides and lignin. We tested extracellular enzyme preparations from 14 species of fungi for saccharification activity and examined the factor for saccharification by statistical analysis.

tified antifungicides. Production and localization of phenoloxidizing enzymes were specific in each dual culture; however, the results differed depending on the pairing of confronted fungi, and no predominance was observed because not all pairings were checked. Here, we used five white-rot fungi that are commonly seen in Japan and examined all pairings of fungus-to-fungus interaction, in accordance with the procedures described by White and Boddy (1992).Five strains of white-rot fungi that are preferential to angiospermous wood were tested: Ganoderma applanatum (Pers.) Karst. (KPUF 0694), Pleurotus ostreatus (Jacq.: Fr.) Kummer (KPUF 2494), Pycnoporus coccineus (Fr.) Bond. et Sing. (KPUF 2094), Schizophyllum commune Fr.: Fr. (KPUF 8805), and Trametes versicolor (L.: Fr.) Quel. (IFO 30340). Dual culture tests of fungus pairs were performed with initial seeding at 5-cm distance on MA media (malt extract, 2%; agar 1.5%) at 28°C. MA medium was used to experiment with the interactive behavior of wood-rotting fungi because the behavior in this culture correlates well with their patterns of occurrence in the field (Griffith and Boddy 1991). After the predominance in confrontation was observed, the localities of laccase and peroxidase were determined by pouring substrate solutions (1.44% a-naphtol in 96% aqueous ethanol, and a mixture of 1% pyrogarol and 0.4% H 2 O 2 , respectively) on the culture plates in accordance with White and Boddy (1992). Figure 1 shows a result of the dual culture with P. ostreatus and S. commune. After confrontation occurred between them, the P. ostreatus colony grew over S. commune and then stopped after expanding into the colony a few millimeters. In most cases, one fungus grew over the other after confrontation and invaded to about 1-2 cm in depth. However, mycelia stopped growing in all cases except for the dual culture of T. versicolor and S. commune, where the former overgrew the latter. In the competition between T. versicolor and P. coccineus, both fungi stopped growing within a few millimeters of the confrontation regions, and mycelia of both became hypertrophic. These observations are summarized in Table 1. Porter (1924) classified the interaction between two fungi into five types. AbstractThe role of the phenol-oxidizing enzymes, laccase and peroxidase, was examined in the fungus-to-fungus interaction in dual cultures. Among five white-rot fungi, the following predominance in competition was observed: Pleurotus ostreatus > Trametes versicolor м Pycnoporus coccineus > Ganoderma applanatum > Schizophyllum commune. Both phenol-oxidizing enzyme activities were detected markedly at the confrontation region, and under the mycelia growing over other colonies more than in other areas of the dual culture. This property was most notably observed in the P. ostreatus cultures. The fungi that produce superior active phenol-oxidizing enzymes were predominant in the competition between confronting fungi, indicating that phenol-oxidizing enzymes relate to fungusto-fungus interaction.Key words Fungus...