Optimization of medium constituents for Glutamic acid production by mixed starter cultures in pig ossein solid state fermentation

The medium constituents for producing Glutamic acid by a mixed starter culture composed of Aspergillus oryzae and Monascus purpureus in pig ossein solid state fermentation were optimized. The effects of carbon sources,nitrogen sources and surfactants on the yield of Glutamic acid and total amino acids were studied by single factor and orthogonal array design methods. Results suggested that the optimal medium constituents were bran concentration of 100 g,pig ossein concentration of 60 g,( NH4)2SO4concentration of 15 g and tripolycerol monostearates concentration of 3 g.Under these conditions,the yields of Glutamic acid and total amino acids were167.8 g / kg and 728.6 g / kg,respectively,after a fermentation 5 days at 30 ℃.