In order to achieve large-scale production of Lactobacillus pentosus, a low-cost and easy to prepare culture medium was determined based on the growth state of the strain. The effect of MRS of Lactobacillus pentosus was simulated in the experiment, and corn steep liquor powder was used as nitrogen source instead of MRS, which could play a better role.

Lactobacillus pentosus is a kind of lactic acid bacteria, which plays an important role in the production of fermented sausage: it can metabolize carbohydrates to produce lactic acid, resulting in low pH value of the product, thus inhibiting the growth of pathogenic bacteria and spoilage bacteria. Bacteriocin can also inhibit the common spoilage bacteria in food, such as bacillus, Staphylococcus aureus, etc.; it can promote the decomposition of nitrite and reduce the possibility of interaction between residual NO2 - and diamine to form nitrite. The final product of its metabolism also gives sausage special flavor. At present, MRS medium is mainly used to culture Lactobacillus pentosus, which is rich in vitamins, nucleotides and other nitrogen sources. Corn steep liquor powder is suitable for the growth of Lactobacillus pentosus.

In the microbial fermentation industry, the cost of fermentation medium accounts for about 30% and 6% of the total cost, while the cost of nitrogen source in MRS medium accounts for about 90% of the total cost. Therefore, cost reduction is mainly to reduce the cost of nitrogen source. Corn steep liquor powder is made from corn steep liquor by-product spray drying, and its cost is low. Its nutritional structure is very suitable for the growth and propagation of lactic acid bacteria. The content of soluble protein, amino acids, vitamins, inorganic salts and other proteins is about 40%, which can be used as nitrogen source of lactic acid bacteria. At the same time, it has a good buffer system to avoid the production of lactic acid bacteria. In MRS medium, phosphate was destroyed. Corn steep liquor powder medium has been successfully used to culture Bifidobacterium. Corn steep liquor powder can reduce the use of phosphate and inorganic salt, which is more suitable for large-scale application.