Pia Bethge

Grain growth and microbial interactions in water kefir

Water kefir is a fermented beverage which is produced by adding water kefir grains to a sucrose solution with dried fruits. The grains, which have a size of approx. 1-10 mm, consist of a polysaccharide matrix and have a jelly-like consistency. They are colonized mainly by lactic acid bacteria, acetic acid bacteria and yeasts that live together in a symbiotic community.      
The grains increase in number and size during fermentation cycles. So far, it has not been possible to clarify how new grains form from existing ones and what dynamics the growth is based on. Therefore, one aim of the project is to establish a method that enables a kinetic growth description and investigate how different parameters affect the growth, development and morphology of the grains.           
The second part of the project addresses the isolation of microorganisms from water kefir and their interactions. The focus is particularly on the interactions that contribute to the grain growth and their structuring.

The project is a collaboration between the Chair of General Microbiology (Prof. T. Mascher) and the Chair of Food Chemistry (Prof. T. Henle) at the TU Dresden.

Since 2021
PhD Student, General Microbiology, Institute of Microbiology, TU Dresden, Germany

2016-2021
Student of Food Chemistry, Technical University of Dresden, Germany, Thesis: “Analysis of glyoxalase 1 in Bacillus subtilis after genetic transformation and in Escherichia coli”
Earned Degree: Diploma in Food Chemistry (Graduate Food Chemist)

In progress…