Mycelial Growth, Biomass Production and Iron Uptake by Mushrooms of Pleurotus species Cultivated on Urochloa decumbens (Stapf) R. D. Webster

Mushrooms absorb minerals and are able to accumulate them as functional organic compounds during growth. Iron is one of the elements required for various metabolic processes but low intake has resulted to some nutritional deficiencies. This study investigated the effect of different iron concentrations in the culture media on mycelial growth, biomass production, hyphae diameter and distance between septa of six species of Pleurotus, namely Pleurotus ostreatus; Pleurotus cornucopiae; Pleurotus djamor; Pleurotus pulmonarius, and Pleurotus djamor v. roseus. These macrofungi were further grown on substrate based Urochloa decumbens with addition of Fe (0, 500 and 1000 mg Kg-1). The mycelial growth rate and biomass produced by Pleurotus species decreased (P<0.05) as iron concentration increased from (0 - 100) mg L-1. This shows an inhibitory interaction between the fungi and iron at higher concentration. The hyphae diameter and distance between septa of the examined fungi were respectively ranged from 45 µm to 80 µm and 40 µm to 119 µm at iron concentration of (0 -100) mg L-1. The estimated iron uptake in cultivated Pleurotus species ranged from 37.8 µg g-1 to 96.6 µg g-1 when 500 mg Kg-1 and 1000 mg Kg-1 of Fe was added to the substrate. The cultivation of edible macrofungi enriched with iron could improve the socio economic status and play a nutritional role in decreasing anemia.