Isolation, identification and characterization of lactic acid bacteria from swine

Abstract:

[Objective] We isolated, identified and characterized lactic acid bacteria (LAB) from the intestinal digesta, mucosa and feces of piglets, to explore the potential probiotic stains for the swine production.[Methods] A total of 155 lactic acid bacteria were isolated. Four isolates with high lactate production were identified by conventional biochemical method and bacterial 16S rRNA sequence, and their potential probiotic properties were assessed.[Results] Four LAB isolates (L45, L47, L63 and L79), Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus johnsonii and Enterococcus facium were identified based on lactate production at 8 h (> 100 mmol/L) and final pH at 90 h (< 3.9). The 4 isolates grew rapidly in vitro. They tolerated low pH and bile salt. Strains L47 and L79 tolerated pH 2.5, and L47 tolerated 0.5% bile salts. When the 4 isolates were co-cultured with E. coli K88 and Salmonella, the growth of E. coli K88 and Salmonella was inhibited. L47 demonstrated stronger inhibition effect than other 3 isolates.[Conclusion] L47 strain presented a higher lactate production, better growth, higher tolerance against pH 2.5 and 0.5% bile salt, and stronger antimicrobial effect on E. coli K88 and Salmonella, indicating that L47 isolate may have the potential probiotic properties for swine production.