Isolation and identification of lactic acid bacteria involved in the spontaneous fermentation of umqombothi

Umqombothi is a traditional alcoholic drink from southern Africa that is enjoyed during social and cultural events.
It is prepared through spontaneous fermentation; however, the microbial communities driving this process still require further exploration.
This study isolated and identified lactic acid bacteria (LAB) involved in umqombothi fermentation while monitoring chemical parameters over a 72-h period.
Samples were collected and analysed at five stages: after mashing; after 24 h of fermentation; after boiling and sorghum inoculation; after a second 48 h fermentation period; and after filtration (final product). Results showed a reduction in total soluble solids (TSS), a significant decrease in pH (from 5.75 to 3.47), and an increase in titratable acidity (TTA). LAB counts on De Man, Rogosa, and Sharpe (MRS) agar increased from 5.27 to 7.30 log CFU mL^‑1, and the total plate count showed a similar trend.
The 16S rRNA gene enabled the identification of isolates, revealing the occurrence of Pediococcus pentosaceus, Lactiplantibacillus plantarum and Weissella confusa, with Pediococcus pentosaceus being predominant throughout the fermentation stages.
This study provides insights into the microbial population and chemical changes during umqombothi fermentation, laying the foundation for optimizing the fermentation process and potentially improving product quality.

IV International Symposium on Beverage Crops

W.A. Tizayi, V.E. Ngoveni, L.A. Nyathi, P.B. Njobeh, O.A. Adebo

umqombothi, sorghum, fermentation, lactic acid bacteria (LAB), brewing

https://doi.org/10.17660/ActaHortic.2026.1466.66