Microbiome composition of kombucha tea from Türkiye using high-throughput sequencing

Kombucha is a fermented tea with a combination of yeast and bacteria. Kombucha teas may have a variable microbiota based on geographic origin and cultural conditions. The microbial flora of kombucha has been studied with culture-dependent methods. But, the improvement of the metataxonomic approach has broadened our perspective on fermented foods. In this study, a kombucha mother was procured from an artisanal supplier in Türkiye. High-throughput new-generation sequencing (16S rRNA and Internal Transcribed Spacer (ITS)) was carried out to investigate the microbial communities of kombucha after 7 days of fermentation in both liquid tea (L) and pellicle (P). Microbial counts, pH (4.42 ± 0.01 and 3.50 ± 0.02), and TA% (0.26 ± 0.02 and 0.60 ± 0.04) were also detected on the first and 7th days of fermentation. According to metataxonomic results, the dominant bacteria were Komagataeibacter obediens (%21.13), an acetic acid-producing bacteria, and the dominant fungal genus was Pichia kudriavzevii (64.35%) in L while Romboutsia sp. CE17 was the dominant bacteria (7%) and Pichia kudriavzevii was also the dominant yeast in P. This study also revealed different species which were not common in kombucha including propionic acid and butyric acid-producing bacteria such as Anaerotignum propionicum and Butyrivibrio fibrisolvens, a butyrivibriocin producing bacteria. Accordingly, different yeast species were detected such as Tetrapisispora phaffii and Ogataea polimorpha.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05725-z.

Changes in the chemical compositions and biological properties of kombucha beverages made from black teas and pineapple peels and cores

Several raw materials have been used as partial supplements or entire replacements for the main ingredients of kombucha to improve the biological properties of the resulting kombucha beverage. This study used pineapple peels and cores (PPC), byproducts of pineapple processing, as alternative raw materials instead of sugar for kombucha production. Kombuchas were produced from fusions of black tea and PPC at different ratios, and their chemical profiles and biological properties, including antioxidant and antimicrobial activities, were determined and compared with the control kombucha without PPC supplementation. The results showed that PPC contained high amounts of beneficial substances, including sugars, polyphenols, organic acids, vitamins, and minerals. An analysis of the microbial community in a kombucha SCOBY (Symbiotic Cultures of Bacteria and Yeasts) using next-generation sequencing revealed that Acetobacter and Komagataeibacter were the most predominant acetic acid bacteria. Furthermore, Dekkera and Bacillus were also the prominent yeast and bacteria in the kombucha SCOBY. A comparative analysis was performed for kombucha products fermented using black tea and a fusion of black tea and PPC, and the results revealed that the kombucha made from the black tea and PPC infusion exhibited a higher total phenolic content and antioxidant activity than the control kombucha. The antimicrobial properties of the kombucha products made from black tea and the PPC infusion were also greater than those of the control. Several volatile compounds that contributed to the flavor, aroma, and beneficial health properties, such as esters, carboxylic acids, phenols, alcohols, aldehydes, and ketones, were detected in kombucha products made from a fusion of black tea and PPC. This study shows that PPC exhibits high potential as a supplement to the raw material infusion used with black tea for functional kombucha production.

Modulation effects of microorganisms on tea in fermentation

Tea is a popular traditional drink and has been reported to exhibit various health-promoting effects because of its abundance of polyphenols. Among all the tea products, fermented tea accounts for the majority of tea consumption worldwide. Microbiota plays an important role in the fermentation of tea, which involves a series of reactions that modify the chemical constituents and thereby affect the flavor and bioactivities of tea. In the present review, the microorganisms involved in fermented tea and tea extracts in the recent studies were summarized and the modulation effects of microorganisms on tea in fermentation, including polyphenols composition and content, biological activities and sensory characteristics, were also critically reviewed. It is expected that the data summarized could provide some references for the development of microbial fermented tea drinks with specific nutrition and health benefits.

Recent advances in Kombucha tea: Microbial consortium, chemical parameters, health implications and biocellulose production

In the present review the latest research studies on Kombucha tea are summarized. Special attention has been paid on microbial population, chemical parameters, biocellulose production, and mainly, on the latest evidences of the biological activities of Kombucha tea. Kombucha tea is a fermented sweetened black or green tea which is obtained from a fermentative process driven by a symbiotic culture of yeast, acetic acid bacteria and lactic acid bacteria. In the last years, its consumption has increasingly grown due to its multiple and potential benefits on human health. This fact has motivated a significant increase in the number of research studies that are focused on the biological activities of this beverage. In this context, this review gathers the main studies that have analyzed the different properties of Kombucha tea (as antioxidant, antimicrobial, antidiabetic, antitumoral, anti-inflammatory, antihypertensive, hepatoprotective, hypocholesterolemic, and probiotic activities). It is highlighted that nowadays few human-based evidences are available to prove the beneficial effect of Kombucha tea on humans' health. In conclusion, further work on Kombucha tea is needed since nowadays few information is available on both clinical studies and the characterization of bioactive compounds and their properties.

Dehydrogenases of acetic acid bacteria

Acetic acid bacteria (AAB) are a group of bacteria that can oxidize many substrates such as alcohols and sugar alcohols and play important roles in industrial biotechnology. A majority of industrial processes that involve AAB are related to their dehydrogenases, including PQQ/FAD-dependent membrane-bound dehydrogenases and NAD(P)⁺-dependent cytoplasmic dehydrogenases. These cofactor-dependent dehydrogenases must effectively regenerate their cofactors in order to function continuously. For PQQ, FAD and NAD(P)⁺ alike, regeneration is directly or indirectly related to the electron transport chain (ETC) of AAB, which plays an important role in energy generation for aerobic cell growth. Furthermore, in changeable natural habitats, ETC components of AAB can be regulated so that the bacteria survive in different environments. Herein, the progressive cascade in an application of AAB, including key dehydrogenases involved in the application, regeneration of dehydrogenase cofactors, ETC coupling with cofactor regeneration and ETC regulation, is systematically reviewed and discussed. As they have great application value, a deep understanding of the mechanisms through which AAB function will not only promote their utilization and development but also provide a reference for engineering of other industrial strains.

Recent Progress in Chemical Composition, Production, and Pharmaceutical Effects of Kombucha Beverage: A Complementary and Alternative Medicine

Kombucha is a valuable traditional natural tea that contains beneficial compounds like organic acids, minerals, different vitamins, proteins, polyphenols, and several anions. Kombucha possesses anticancer, antioxidant, antimicrobial, and antifungal activity as well as hepatoprotective effects. Considering the unique properties of Kombucha, several investigations have already been conducted on its nutritional properties. In this review, an effort has been devoted to pool recent literature on the biomedical application of Kombucha under the objectives, including the chemical composition of Kombucha and industrial production, and highlight different properties of Kombucha. Finally, we explain its adverse effects and prospect. This review is an active, in-depth, and inclusive report about Kombucha and its health benefits.