Nutrient Uptake in Supplemented Substrate by Oyster Mushroom

Abstract Spent mushroom substrate (SMS) can be a good alternative for the supplementation of the Oyster mushroom substrate, replacing the cereal bran normally used. Therefore, the objective was to evaluate the production of Pleurotus ostreatus supplemented with Lentinula edodes’ SMS, through the nutritional analysis of the substrate. Wheat straw was used as substrate and supplemented with rice bran (RB) or SMS in 0%, 7%,15% and 30%. Ca, K, Mg, Mn, Zn, Cu and Fe contents of the cultivation substrates (before and after harvest) were determined . Mycelial growth (cm²/day), mycelial time colonization (days), number of clusters, number of pileus, average clusters weight (g), pileus lenght (cm) and width (cm), productivity (1 st , 2 nd and 3 rd flush) (%), biological efficiency (%) of mushrooms were evaluated. Results indicated mycelial growth was higher when the substrate was supplemented regardless of the source. The same tendency followed for second flush (%), third flush (%), average clusters weight (g), productivity (%) and biological efficiency (%). The proportions of 15% of SMS achieved the highest biological efficiency. All the nutrients analyzed had a decrease in their concentrations. The only nutrients that showed differences in absorption according to each substrate used were Ca, K and Mn. This difference was also noticed according to the type of supplement, in which substrates supplemented with SMS had greater absorption of Ca, while substrates supplemented with RB absorbed more K. It is noteworthy that the mineral contents in substrates directly affect the production of P. ostreatu s, which implies that the SMS are a nutritional source in terms of mineral contents and thus can be recycled and used to replace rice bran and produce Oyster mushroom.