Preparation method of bacteriocin-producing Lactobacillus plantarum subsp. Plantarum Zhang-LL active bacterial preparation

The invention relates to a preparation method of a bacteriocin-producing Lactobacillus plantarum subsp. Plantarum Zhang-LL active bacterial preparation, and belongs to the field of microbe application. In the preparation method, by using a bacteriocin-producing Lactobacillus plantarum subsp. Plantarum Zhang-LL CGMCC No. 6936 bacterial strain, the active bacterial preparation is prepared through activation, expanding culture, high-density fermentation, centrifugation, freeze-drying protective agent addition, a prefreezing process, a freeze-drying process and other processes. The preparation method comprises the following steps: firstly, rapeseed peptone is selected as a substituting nitrogen source, so that the culture condition of the lactobacillus plantarum is optimized while the cost of a culture medium is reduced; a 5L of full-automatic fermentation tank is used for performing the high-density fermentation, and under the optimized low-cost culture medium and the optimized culture condition, the viable count of fermented liquid can reach above 1010CFU/mL. In the preparation method, potato pulp is used as a matrix of a freeze-drying protective agent, and an optimal combined formula of the freeze-drying protective agent is determined, so that the survival rate of the Lactobacillus plantarum subsp. Plantarum Zhang-LL reaches above 60% and the viable content can reach above 1011CFU/g. The prepared active bacterial preparation is low in raw material price and relatively high in viable content, can provide a good foundation for developing a novel feed additive for poultry, and can provide a significant economic value.