1. Using several species of wood-destroying fungi, the respiration of each fungus on various media was determined. And from the results of the respiration intensity shown by the fungi, the utilization of the carbon sources in the media is discussed.
2. Sugars both hexoses and pentoses, are utilized as metabolic substances by all the fungi used.
3. Phenolic compounds are mostly toxic for the fungal metabolism. Among them, catechol, chinon, salicylic acid and benzoic acid showed severe toxicity for all the fungi. On the other hand, some compounds appeared to be utilized by certain fungi. For example, para hydroxybenzoic acid is toxic for Polyporus japonicus and also for P. Schweinitzii, but efficiently available for Polystictus sanguineus. This fact shows that the wood-destroying fungi can decompose the benzene nucleus and consume these aromatic compounds as their metabolic substances.
4. Wood-destroying fungi can generally respire in an anaerobic condition. So far as the present experiment goes, the anaerobic respiration shown by cellulose-specialists is greater than that of the lignin-specialists.