Abstract:Lactiplantibacillus plantarum J26 was used as the research object. The carbon and nitrogen sources were screened using the Biolog GEN III Microstation automated microbial identification system. After optimization, a mixture of 25 g/L maltose and glucose (1:1) was used to replace the carbon source in the MRS medium, and a mixture of 10 g/L beef paste and yeast powder (1:1) was used to replace the nitrogen source in the MRS medium. The optimal fermentation conditions for the strains determined by single factor experiment were as follows: initial pH of the medium, 5.6; fermentation temperature, 33 ℃; inoculation amount, 4%. Under these conditions, a 5-liter fermenter was used for high-density fermentation. Lactiplantibacillus plantarum J26 reached the stable stage after 14 h of fermentation, and the viable cell count could reach 4.35×1010 CFU/mL. Because Lactiplantibacillus plantarum J26 has a high viable cell count and high fermentation activity, thus can be used as a starter for the fermentation of soy milk. Fermented soy milk with a good viable bacterial count (3.56×108 CFU/mL), water-holding capacity (48.12%), and textural characteristics was obtained. By optimizing the highdensity fermentation process, the number of viable bacteria in the fermentation broth can be effectively increased. This provides a theoretical basis for the application of high-density fermentation with Lactiplantibacillus plantarum J26 and the industrialization of fermented soy milk.
