Kombucha tea fermentation: Microbial and biochemical dynamics

Authors:
Somnath Chakravorty, Semantee Bhattacharya, Antonis Chatzinotas, Writachit Chakraborty, Debanjana Bhattacharya, Ratan Gachhui

Abstract:
Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties would change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup, however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~ 50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage, such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher d-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentation. Our data thus indicate that the microbial community structure and dynamics play an important role in the biochemistry of the fermentation of the beverage. We envisage that combined molecular and biochemical analyses, like in our study, will provide valuable insights for better understanding the role of the microbial community for the beneficial properties of the beverage.

Keywords: kombucha tea, microbial community structure and dynamics, high throughput sequencing, t-rflp, change in fermentation, radical scavenging



Country: India

Citation: International Journal of Fod Microbiology, Vol 220

Study Mailing Address:
Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S. C. Mallick Road, Kolkata 700032, India

Date Updated: March 11, 2020