Utilization of wastes from grain processing industries

Abstract

Waste materials resulting from the grain processing industries are harmless and easily amenable to enzymatic and microbial bioconversions. Basidiomycetous mushrooms grown in vitro are promising producers of protein and essential amino acids. Mushroom biomass production under appropriate cultivation conditions using agricultural by-products is a cheap and affordable way to obtain a high-quality food product. The present work explores the possibility of using grain wastes for the cultivation of golden oyster mushrooms under deep cultivation conditions. For these purposes, cornmeal was used as a source of carbon waste and gluten as a source of nitrogen. A high substrate colonization rate was observed. The fruiting cycle lasted about 26 to 28 days on the studied substrates. The most prolonged cycles were obtained on the medium supplemented with sawdust. The maximum and the minimum yields were obtained on wheat straw substrate (171.2 g per kg of substrate) and a grain waste substrate (113.4 g per kg) respectively. On birch sawdust subtrate and on a substrate of grain waste and birch sawdust mixture, the yields reached 143.2 g and 130.3 g in this order. The average yielding crop attained 113.4 g of fresh mushrooms grown on 1 kg of substrate under a relative humidity of 70-75%. This promising work stream not only proposes a waste disposal method, but also, a significant source of income for the grain processing enterprises.