Article written by Cosme Damião Barbosa, biologist, PhD student in Food Science at the Federal University of Minas Gerais (UFMG)

Kombucha is a fermented beverage of Asian origin. Originally produced from the fermentation of the infusion of green tea or black tea (Camellia sinensis) by the action of yeasts and bacteria of acetic acid. Its consumption began in the region of China in 220 BC, being popularized in Europe and North America only in the middle of the 20th century.

The microbial composition of kombucha can vary in relation to the source and origin of the inoculum (inoculum from different places differ in microbial composition), as well as other factors such as fermentation temperature, initial load of fermentative microorganisms and manipulation of the inoculum. During the fermentation process, several compounds are formed, such as: ethanol, acetic acid, gluconic acid, glucuronic acid and others, resulting in a sweet, slightly acidic and naturally carbonated drink. The consumption of kombucha has been linked to claims of anti-inflammatory (Jayabalan et al. 2014), antioxidant (Chu and Chen, 2006; Bhattacharya et al., 2013), antimicrobial activity (Greenwalt et al, 1998, Sreeramulu et al. , 2000; Bhattacharya et al., 2016, Vitas et al; 2018), anticarcinogenic (Jayabalan et al. 2011) among others. Recently, kombucha consumption has been linked to weight loss, intestinal regulation and probiotic action. However, there are still no scientific reports to prove such claims, especially the presence and action of probiotic microorganisms.

Recent studies demonstrate that the chemical composition of the kombucha, as well as the composition of its microbiota (microorganisms in the kombucha) is strongly influenced by the temperature of preparation. The characterization and analysis of the kombucha microbiota opens a field of possibilities that are related from the optimization and control of the process to the presence of microorganisms of biotechnological and industrial interest. There are no publications in the literature that address the composition of the inoculum microbiota of Brazilian origin. Therefore, the objective of this doctoral proposal is to characterize the fermentation process of kombucha and the “Brazilian” inoculum microbiota by dependent and independent cultivation techniques. This approach can provide answers regarding the constitution and viability of the inoculum, in addition to promoting actions for the standardization of the fermentation process, constitution of a possible starter culture or the presence of microorganisms with potential use in biotechnological areas. 

Part of my essays were carried out in partnership with Professor Paula Teixeira and supervised by Helena Albano from the Center for Biotechnology and Fine Chemistry at Escola Superior de Biotecnologia at Universidade Católica do Porto. The manuscripts are in the drafting stage and soon we will have this information widely disclosed.