Abstract:

Using single factor and orthogonal array designs, the optimal fermentation conditions for antibacterial substances
produced by Lactobacillus pentosus S1-4 and their antibacterial spectrum were studied. The results showed an inoculum
amount of 2.0%, an initial pH of 5.5, and 26 h cultivation at 30 ℃ proved optimal. The average diameter of inhibition zones
against Lactobacillus brevis under the optimized culture conditions was (30.08 ± 0.69) mm, and the bacteriostatic activity
was increased by 1.23 times over that before optimization. The antibacterial substances produced by Lactobacillus pentosus
S1-4 were effective against 12 strains of Gram-positive and Gram-negative bacteria, indicating a wide antibacterial spectrum.
In conclusion, S1-4 has potential applications as a bio-preservative to improve the safety of food products.

Key words: Lactobacillus pentosus, antibacterial substance, fermentation conditions optimization