Izolacija i karakterizacija mikrobiote tijekom fermentacije kombucha zelenog čaja

undergraduate thesis

• Title (english): Isolation and characterization of microbiota during green tea kombucha fermentation
• Author: Nensi Zelić
• Mentor: Sunčica Beluhan (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2023-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Kombucha čaj, funkcionalni napitak koji se pripravlja pomoću simbiotske kulture bakterija i kvasca (SCOBY), poprima značajan interes zbog svojih blagotvornih svojstava. Mikrobiota kombucha čaja sastoji se od bakterija i osmofilnih kvasaca, prisutnih u dva međusobno neisključiva dijela: tekućoj fazi ili napitku i biofilmu (bakterijska nanoceluloza, BNC) koji pluta po njoj. U ovom je radu istraživana struktura i dinamika mikrobne zajednice i biokemijska svojstva kombucha čaja tijekom 14 dana fermentacije zelenog čaja. Tijekom fermentacije u zelenom čaju zaslađenom saharozom (80 g/L) praćene su promjene pH vrijednosti, stvaranje organskih kiselina (octene i glukonske), etanola i prinos sintetizirane BNC. Rodovi bakterija koji se izolirani iz SCOBY kulture su Acetobacter, Gluconacetobacter, Micrococcus i Serratia, dok su Rhodotorula, Schizosaccharomyces i Candida glavni izolirani rodovi kvasaca. Kombinirane mikrobiološke i biokemijske analize dale su vrijedne uvide u bolje razumijevanje uloge mikrobiote u korisnim svojstvima kombucha zelenog čaja.

Abstract (english)

Kombucha tea, a functional beverage brewed through a symbiotic culture of bacteria and yeast (SCOBY), is acquiring significant interest due to its claimed beneficial properties. The microbiota of kombucha tea consists of bacteria and osmophilic yeasts, which thrive in two mutually non-exclusive parts: the liquid phase or the beverage and the biofilm (bacterial nanocellulose, BNC) floating on it. In this study, we explored the structure and dynamics of the microbial community and the biochemical properties of kombucha tea at different time points up to 14 days of green tea fermentation. Changes in pH value, the formation of organic acids (acetic and gluconic), ethanol, and synthesized bacterial nanocellulose (BNC) yield were observed over fermentation in sucrose-sweetened green tea (80 g/L). Genera of bacteria majorly found in the SCOBY are Acetobacter, Gluconacetobacter, Micrococcus, and Serratia, while Rhodotorula, Schizosaccharomyces, and Candida were the major yeasts genera isolated. A combined microbiological and biochemical analyses were provide valuable insights to understand better the microbiota's role in the kombucha green tea beneficial properties.

• Keywords: kombucha; mikrobiota; SCOBY; bakterijska nanoceluloza
• Keywords (english): kombucha; microbiota; SCOBY; bacterial nanocellulose
• Language: croatian
• URN:NBN: urn:nbn:hr:159:698434
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-04-30 08:57:55