Zs. P. Komáromy szerk.: Studia Botanica Hungarica 13. 1979 (Budapest, 1979)
Révay, Ágnes: The metabolism of Pleurotus ostreatus (Jacq. ex Fr.) Kummer, Pleurotus florida Block and Pleurotus cornucopiae Paul. ex Fr. from taxonomical and other viewpoints
SUMMARY 1. The mycelium growth and its turning into fruit in the fungus species examined influenced by the substrates of cultivation. 2. The rate of interweaving was fastest in the corn stalk then the factory mixture and straw (Table 1). In these, the initial free sugar content is high (corn stalk, straw), or the cellulose content is high (factory mixture). 3. The utilization of saw-dust, although this is the natural substrate of fungi, is not rapid, according to our examinations; the mycelium growth is slow and its production is low, in spite of the high cellulose and lignin content (Table 6). 4. It can be inferred that all the three Pleurotus species utilize the sugar content of the substrate at the initial phase of the interweaving, influenced to a certain extent by the initial composition of the substrate. 5. The decomposition of the lignin in Pleurotus florida is always the most intensive in the phase of interweaving, which at the phases slowly decreases. The lignin utilization in Pleurotus ostreatus in most substrates is similar to that of Pleurotus florida, but in sorghum stalk the lignin utilization increased also during the formation of fruit bodies. 6. The decomposition of cellulose in Pleurotus florida is highest just before the formation of fruit bodies, irrespective of the substrate, while in Pleurotus os treatus the highest decomposition of cellulose occurred during the phase of interweaving, in sorghum stalk and corn cob. 7. The fungus species examined are rather cellulolytic than lignin utilizers, this is especially true for the physiological phase of interweaving and for that preceding the formation of fruit bodies. 8. Beside the morphological and ecological differences between Pleuro tus ostreatus and Pleurotus florida, the latter resembles in structure that of Pleurotus ostreatus, but is somewhat smaller and finer. The cap colour is pale yellow, whitish, as against of the greyish-brown, slate-grey colour of Pleurotus ostreatus 1 cap (ZADRAZIL 19 74). The formation of Pleurotus ostreatus 1 fruit bodies requires cold-treatment of about 10 days, at 5-6° C (ZADRAZIL-SCHNEIDEREIT 1972); the species deviations can be detected also in carbon metabolism. The breaking-down of substrates is basically similar, but in Pleurotus ostreatus , the degree of cellulose and lignin decomposition is more influenced by the ratio of compositions of the initial substrates, than in Pleurotus florida. 9. Species differences occur also in the substrate utilization, which is shown by the Pleurotus florida' s faster interweaving and producing of fruits. 10. Pleurotus cornucopiae in our examinations differed from the other two by its greatest initial lignin consumption. The degree of its cellulose utilization is at the same time similar to that of Pleurotus ostreatus. Its initial sugar consumption is smaller compared with that of the others, while its lignin utilization at the same time is higher. 11. Considering the rate of interweaving and the morphological picture of mycelium in Pleurotus cornucopiae , the nutrient utilization is not so intensive as that other two species. 12. The results of these examinations, i.e. the ratio of the utilization of main internal contents, the rate of interweaving, the production of mycelium,
