چکیده (انگلیسی):

To study on mixed fermentation of probiotics, bacterial cultivation was carried out firstly. It was showed that the optimal pH values for growth of Lactobacillus, Yeast and Bacillus subtilis were 6.5, 6.0 and 7.0, respectively. And the suitable temperature for all of them was about 31°C. Then under selective conditions pH 6.0, 31°C and 160 r/min, three probiotics were cultivated by taking Lactobacillus as main bacteria and the others as auxiliaries. It was found that the desired bacterial number ratio of Lactobacillus: Yeast: Bacillus for mixed cultivation was 1:2:2 and the OD value of mixed bacterial solution achieved at 2.27 after three days.