Optimization of Diosgenin Production by Mixed Culture Using Response Surface Methodology

Optimization of four process parameters was attempted using Box-Behnken design for production of diosgenin by a mixed culture with Aspergillus oryzae, Phanerochaete chrysosporium, and Aspergillus niger. Maximum diosgenin yield of 42.89 +/- 0.53 mg/g was obtained after optimization of culture conditions such as Dioscorea zingiberensis C. H. Wright (DZW) concentration 42.98 g/l, inoculum size 1.73 ml of spore suspension (1: 2: 3 ratio of A. oryzae, P. chrysosporium, and A. niger), initial pH 5.0, and cultivation time 5.27 days (127 h) and incubated at 30 degrees C on a rotary shaker set at 180 r/min as mixed culture.