Comparative quantitative analysis of probiotic bacteria during puer tea pile fermentation

Abstract

To explore the function of probiotic bacteria in puer tea pile fermentation which was implemented by a symbiosis of many fermenting microbes and enzymes, the species, abundances and dynamics of probiotic bacteria were quantitatively investigated. Using the real-time quantitative PCR (qPCR) primers specifically targeting different genera bacteria, the results showed that Enterococcus spp., Lactococcus spp., Lactobacillus group and Bacillus spp. were all found at 0, 15, 30, and 45 days during the fermentation, but Bifidobacterium spp. was not involved throughout the fermentation. Furthermore, among these four genera, Lactococcus spp. was the predominant probiotic with population of 1.68 × 109–2.78 × 109 copy g−1 in the fermentation, followed by Enterococcus spp. harboring 3.43 × 104–6.25 × 105 copy g−1, and Lactobacillus group and Bacillus spp. had 4.26 × 103–5.17 × 104 and 2.21 × 103–2.31 × 105 copy g−1, respectively. In addition, the dynamics of four genera probiotic bacteria and universal bacteria were explored to show completely different and complex change trends with no significant correlation with pH of tea and each other. Population dynamic studies of probiotic bacteria revealed their ecological feature and importance for puer tea pile fermentation, and also facilitated further exploration of probiotic resources and health benefits of puer tea.