Effect of Selenium Biofortification in Cultivation Material on Selenium Content of White and Grey Oyster Mushroom (Pleurotus ostreatus (Jacquin Fries) P. Kummer)

Abstract

     Oyster mushroom (Pleurotus ostreatus) is a popular edible mushroom due to its chewy texture, deliciousness and nutritional value including high protein, low fat, and varieties of micronutrients. Selenium (Se) is an important micronutrient that maintains proper function of various systems in human and animals, and delays aging of cells. In fact, mushrooms contain more Se than other food crops, however, Se content of mushrooms varies due to their growing substrates. This study aimed to increase Se content in two types of oyster mushroom, white- and grey-, by utilizing Se-rich rice straw and Se fertilizer augmented sawdust as growing substrates. The effect of substrate fertilization was examined using a Completely Randomized Design (CRD) with 10 replications, consisting of 4 treatments (T1 sawdust, T2 sawdust+Se fertilizer 3 mg/kg, T3 conventional rice straw, and T4 Se-rich rice straw). The results indicated that grey mushroom obtained from T1- and T2 substrates were not significantly different in their size and yields, however, they exhibited increased accumulation of Se in their fruiting bodies. Se content of white- and grey mushroom derived from T2 were 28,755 and 26,460 mg/kgDW, respectively, which may indicate excessive accumulation, whereas, white- and grey mushrooms derived from T4 exhibited Se concentrations of 114.28 and 189.08 mg/kgDW, respectively, which is probably a more suitable range. Our findings revealed a potential for using Se-rich agricultural residues to produce Se-enriched mushrooms. It also provided a new cultivation method for Se-enriched oyster mushroom production by Se biofortification for use as quality raw materials for health food and supplement products.