Abstract:Bee bread, a fermented mixture of plant pollen, honey and bee saliva, is a natural and nutritious food. A total of 61 strains of Lactobacillus were isolated from the bee bread and identified as Lactobacillus kunkeei by 16S rRNA gene sequencing. The activity of 61 strains of L. kunkeei to degradate cholesterol was detected by ortho-phthalaldehyde (OPA) method. The degradation rates of 5 strains among them were higher than 15%, and the cholesterol degradation rate of B35 reached (29.07±1.30)%. The 5 L. kunkeei strains were further studied to investigate their probiotic characteristics including acid resistance, bile salt tolerance, antibiotic resistance and bacteriostatic activities. Their acid and bile salt resistance tests showed that 5 strains of L. kunkeei had good acid and bile salt tolerance. The antibiotic susceptibility test results showed that the 5 L. kunkeei strains were sensitive to four clinically significant antibiotics including erythromycin, kanamycin, norfloxacin and vancomycin. The antibacterial activity to gram-positive and gram-negative of 5 L. kunkeei strains was tested by agar diffusion method. All the 5 strains inhibited the growth of Escherichia coli and Staphylococcus aureus. The adhesion rate of strain B35 to Caco-2 cells in vitro was 3.32%. In this study, 5 L. kunkeei strains isolated from bee bread showed good probiotic performance, of which strain B35 had the best probiotic properties. This study offers new bacteria sources for the development and utilization of probiotics.
