Effect of diverse yeast extracts and yeast peptone on growth of acetic acid bacteria cultures

The increasing focus on using defined acetic acid bacteria starter cultures for fermenting beverages, such as kombucha, requires the development of optimal media solutions. In this study, Ohly demonstrates the role of X-SEED® yeast extracts, and yeast peptone, in enhancing the growth of acetic acid bacteria.

Does not contain GM-ingredients
Vegan / Vegetarian
Gluten free

Traditionally, the production of naturally fermented beverages has involved using undefined consortia of microorganisms. With kombucha, this usually comprises acetic acid bacteria, yeast and, in some cases, lactic acid bacteria. However, this use of undefined cultures can present challenges for industrial production, particularly in relation to process consistency and product stability in terms of taste and shelf life.

For this study, in collaboration with Versuchs-und Lehranstalt für Brauerei in Berlin (VLB) e.V., Ohly investigated the influence of different yeast extracts on biomass production of Komagataeibacter hansenii. It was shown that the use of X-SEED® KAT and also X-SEED® Peptone resulted in increased biomass formation. The positive effects were seen in typical growth culture media and also in media containing tea-derived inhibitory compounds.

Further comparisons showed the effectiveness of X-SEED® KAT in enhancing sugar consumption, ensuring balanced organic acid production and an overall increase in the rate of fermentation. Findings from the study can also be applied to other fermented foods and beverages involving acetic acid bacteria.

Main Observations

  • In order for starter culture production to be industrially viable, efficient culture media are required to provide all the necessary nutrients for microbial growth
  • The application of X-SEED® KAT and X-SEED® Peptone yeast derivatives was highly beneficial for biomass production of Komagataeibacter hansenii Ko-0201.
  • Specifically, X-SEED® KAT was able to overcome some of the inhibitory effects of tea on bacterial growth, suggesting it might be particularly useful in the production of kombucha to enhance fermentation productivity and lower batch times.
  • The type of yeast extract used during culturing of acetic acid bacteria plays a crucial role in achieving high biomass titres, quick sugar consumption and the desired organic acid consumption.
  • Both high and low pH ranges yielded similar biomass outputs

Download the white paper

Are you interested in learning more about the distinctive properties of X-SEED® KAT? Please click below to download our white paper and read a full description of the experiment and data.