Study On Cultivation Conditions Of Bacillus Licheniformis TS-01

Bacillus licheniformis TS-01 separated by Institute of Animal Science, China Academy of Agriculture Science and identified by Institute of Microbiology, Chinese Academy of Sciences, can be used as a strain of feed probiotics ,whose effectiveness has already been proved by feed experiments. In order to realize industrial production of Bacillus licheniformis TS-01,liquid state cultivation conditions of Bacillus licheniformis TS-01 were studied; at the same time,solid state cultivation for this strain was also preliminarily investigated.Seed culture conditions of Bacillus licheniformis TS-01 were firstly investigated. The results showed that the optimal growth temperature was 40C;the suitable seed culture medium was beef extract soya peptone medium; the optimal initial pH was 7.5; the optimal seed culture time was 13h~14h.Liquid state medium was optimized through orthogonal experiment and one-factor experiments.The suitable medium contained (g/L): corn power 14, soybean power 46, corn steep liquid 3, MgSO4.7H2O 2, MnSO4.H2O 0.04. Initial pH and inoculum size were also investigated by one-factor experiments. The results were 6.5 , 10%~15% respectively. Flask cultivation time was 30h or so. After the cultivation for 26h at 40℃;in a 100L fermentor, a spore concentration of 1.07×1010 CFU/mL was obtained with a spore percentage of greater than 93% and a maximum live cell concentration of 1.14×1010CFU/mL.Solid state medium was optimized through orthogonal experiment.The suitable medium contained (g/kg dry solid material): water 600, brown sugar 7, rice bran 420, wheat bran 580. when the optimal medium and inoculum size 10%(v/w) were adopted, a spore concentration of 7.50109 CFU/g (wet qu) was obtained after two days' cultivation in a shallow pan with a spore percentage of greater than 80% and a maximum live cell concentration of 9.15×109 CFU/g (wet qu).