Abstract: This study aimed to select cryotolerant lactic acid bacteria with bioprotective potential and to investigate their low-temperature adaptability and bacteriostatic properties. The results demonstrated that Pediococcus acidilactici L1 and Lactiplantibacillus plantarum HG1-1 exhibited a higher tolerance to low temperatures (4 and 7 ℃) when compared with Latilactobacillus sakei B2. In addition, they maintained high activities of superoxide dismutase and protease, as well as good morphological integrity. These two strains significantly inhibited the growth of common spoilage bacteria (Staphylococcus epidermidis, Acinetobacter baumannii, and Brochothrix thermosphacta) in meat products and their inhibitory capacity was substantially higher than that of the commercial strain L. sakei B2. The extracellular metabolites of the two strains retained antibacterial activity after heat treatment at 85 ℃. Trypsin treatment significantly decreased the bacteriostatic activity of the metabolites. Moreover, the bacteriostatic activity of both strains decreased as the pH level increased, disappearing at pH 7. In conclusion, both P. acidilactici L1 and L. plantarum HG1-1 have bacteriostatic activity under low-temperature conditions, showing potential as bioprotectants for low-temperature meat products.

Key words: lactic acid bacteria; low-temperature adaptability; antibacterial activity; bioprotective bacteria; spoilage bacteria