Fermentation of Brewers’ Spent Grain by Effective Microorganisms to Produce Proteins Feed

Abstract

Deep fermentation of brewer's spent grain (BSG) can improve its feeding effectiveness, and it is also an effective way to solve the problem of shortage of proteins source. The interrelated factors affecting the productivity of proteins in fermentation process by effective microorganisms (EM), such as inoculum size, temperature, initial pH and time, were studied and the technique to produce protein feed was also optimized by a serial of single factors and orthogonal design tests. Results showed that the optimal conditions were 4 % of inoculum size, 28 °C of fermentation temperature, 4.0 of initial pH and 3 d of the fermentation time. Under the obtained optimum fermentation conditions, the content of crude proteins increased by 24.48 % and the content of crude fiber decreased by 17.45 % compared with the control experiment. The increased content of proteins indicated the added-value products in animal feed and the significance in its disposal as an environmental problem.