The research on high density culture of Lactobacillus acidophilus

In order to increase the counts of L.acidophilus, the culture medium was optimized by quadratic design, based on the nutritional needs. The composition of optimum culture medium was as following: 1% lactose, 1.5% peptone, 30% carrot juice, 30% plerotus sapidus juice, 1% beef extract, 1% yeast extract, 1% K2HPO4, 1 mL/L Toween-80. In addition, the optimal culture temperature and constant pH are respectively 42 ℃ and 5.5. Under these conditions, adding feeding after L.acidophilus was cultured 9 hours, the counts could reach 8.82× 109 cfu/mL in the 15 hours.