Abstract:This research was designed to optimize the culture medium for Bacillus mucilaginous in submerged fermentation.With spore yield as indicator,the test was divided into three phases.Firstly,based on the results of single factor experiments,the optimum carbon source,nitrogen source and metallic ion and their concentrations were screened and the optimal values of single factors were obtained;secondly,quadratic regression orthogonal rotation composite design was used to optimize the medium further and got the model;then,verification tests were carried out to verify the model.The results showed that the optimal culture medium were(per liter):lactose 21.57 g,combined nitrogen source 2.6 g(ratio of peptone to ammonium sulphate was 1∶3),MnSO4 0.21 g,K2HPO4 1.5 g,MgSO4.7H2O 1.2 g;cultured with the optimal medium,the spore number of Bacillus mucilaginous reached 3.44×10 9 cfu/mL;the ratio of actual spore yield to predicted value was 0.977,indicated that the model was reliable.The results could provide references for the producing of Bacillus mucilaginous.
