Diversity and antimicrobial activity of intestinal lactic acid bacteria isolated from Gymnocypris przewalskii

Abstract:

[Objective] To understand the diversity and antimicrobial activity of intestinal lactic acid bacteria isolated from Gymnocypris przewalskii. [Methods] We identified 47 lactic acid bacteria by the physiological and biochemical properties (pH, temperature and salt resistance) and sequence analysis of 16S rRNA gene. Antibacterial activity of representative strains of lactic acid bacteria were detected. [Results] We identified 23 strains as Lactobacillus fuchuensis (48.94%), 12 strains Lactobacillus curvatus (25.53%), 3 strains Leuconostoc fallax (6.38%), 2 strains Lactobacillus sakei (4.26%), 2 strains Weissella ceti (4.26%); 2 strains Lactococcus cremoris (4.26%), 1 strains Leuconostoc lactis (2.13%), 1 strains Weissella minor (2.13%), and 1 strains Enterococcus devriesei (2.13%). Groups A, B and C could grow between 5 and 50 °C. Groups B and C could grow between pH 3.0 and 10.0. Almost all of the lactic acid bacteria were resistant to 6.5% Nacl concentration. The supernatant could inhibit the growth of indicator strains. By excluding hydrogen peroxide and organic acid, we found that it still has antimicrobial activity. The inhibitive activity decreased after treatment with pepsin, which indicated that this inhibitory material had the features of protein. It could be classified as bacteriocin. [Conclusion] G. przewalskii intestine adhesion diversity of lactic acid bacteria, which will provide quality resources for probiotic lactic acid bacteria and data reference.

Key words:Lactic acid bacteria, Gymnocypris przewalskii intestine, Antimicrobial activity