Utilization of local agro-industrial by-products based substrates to enhance production and dietary value of mushroom (P. ostreatus) in Ethiopia.

Food insecurity and malnutrition are serious problems in many developing countries, including Ethiopia. This situation warrants an urgent need for the diversification of food sources with enhanced productivity. This study was aimed at contributing to the food security in Ethiopia through cultivation of Pleurotus ostreatus mushrooms using sustainable and locally available agro-industrial byproduct-based substrates in parallel with pollution control. Ten substrates were prepared using sugarcane bagasse, filter cake, trash, cotton seed hull and animal waste, namely cow dung and horse and chicken manure. The effect of each substrate (treatment) on the yields, biological efficiency, nutritional composition, and mineral contents of Pleurotus ostreatus mushroom species was evaluated at the Ethiopian Forest Products Innovation Center, Addis Ababa, Ethiopia. The results obtained indicate that a significantly higher (p < 0.05) yield and biological efficiency were recorded from the mushroom cultivated on S2 substrate containing a mixture of 80% sugarcane bagasse, 12% cow dung, and 8% cotton seed hull. Moreover, substrate containing sugarcane bagasse mixed with cotton seed hull, cow dung, and chicken manure significantly (p < 0.05) increased the yields and biological efficiency of the mushroom. The content of protein, crude fat, fiber, and carbohydrates of the mushroom cultivated from all the utilized substrates were in the range of 17.30-21.5, 1.77-2.52, 31.03-34.38, and 28.02-39.74%, respectively. The critical macro-elements are abundant in the mushroom in the order of potassium, magnesium, calcium, and sodium. The mushrooms cultivated on all the substrates were rich in essential micro-elements in the order of iron and zinc. It was found that substrate preparation and formulation significantly (p < 0.05) improved the yields, biological efficiency, nutritive values, and mineral contents of the mushroom. The use of these by-products as substrates is sustainable and environmentally friendly and allows the production of mushroom with high nutritional value on a sustainable basis in order to enhance food security in the country.