Evaluation of Yield, Heavy Metals and Vitamins Compositions of Pleurotus Pulmonarius (Fries) Quell Fruit Bodies Cultivated on three Deciduous Tree Logs

Author(s): Nwoko MC, Achufusi JN, Ahaiwe MC, Ehumadu CR

Studies were conducted to determine the yield potential, vitamins and heavy metals concentrations of Pleurotus pulmonarius (Fries) Quell. fruit bodies cultivated on different wood logs. Pure mycelium culture of P. pulmonarius was aseptically multiplied using sorghum grains. Fully colonized spawn was used to inoculate Mangifera indica, Dacryodes edulis and Treculia africana logs and incubated in the dark room of a mushroom house at 27°C ± 2. Data were subjected to analysis of variance (ANOVA), while comparison between different means were done using Duncan multiple range test (DMRT) at p<0.05 level of significance. Fruit body primordia of the oyster mushroom were first observed in D. edulis logs, followed by T. africana and then M. indica logs after 9, 10 and 12 days of inoculation respectively. T. africana gave the highest yield (156.0967 gm/kg) and Biological efficiency (0.836%) of P. pulmonarius fruit bodies while D. edulis was lowest at 62.3667 gm/kg and 0.200% biological efficiency. Fruit bodies of M. indica had the highest (3.19mg/kg) Zn content; slightly higher than those of T. africana (3.14mg/kg), while fruit bodies from D. edulis gave the lowest Zn (2.96mg/kg) concentration. Fe was significantly (p < 0.05) higher than other heavy metals studied in all the fruit body samples from the log substrates. Mushrooms of D. edulis gave the highest (184.87mg/kg) Fe concentration while those of M. indica gave the lowest (182.91mg/kg). Results showed that D. edulis fruit bodies gave the highest vitamin A content (4.33mg/100g) while M. indica (4.17mg/100g) gave the lowest. However, thiamine content of the mushroom was 0.13mg/100g in D. edulis and T. africana but 0.12mg/100g in M. indica. Mushroom growers should harness the wisdom of this wonderful innovation by utilizing wood logs first, before they can be used for other domestic purposes, such as fire wood.