Bacterial community dynamics in lait caillé, a traditional product of spontaneous fermentation from Senegal

PLoS One. 2019 May 10;14(5):e0215658. doi: 10.1371/journal.pone.0215658. eCollection 2019.


Spontaneously fermented food products contain a complex, natural microbial community with potential probiotic activity. The addition of a health-promoting, probiotic bacterium to these products ensures the delivery of that probiotic activity to consumers. Here, we assess the microbial community of a traditional Senegalese milk product produced by spontaneous fermentation, called lait caillé. We produced the lait caillé in a traditional way and added a probiotic starter containing Lactobacillus rhamnosus yoba 2012 to the traditional process. We found various species that are known for their ability to ferment milk, including species from the genera Lactobacillus, Acetobacter, Lactococcus, and Streptococcus. Our results show that the addition of L. rhamnosus to the inoculum, can result in detectable levels of this strain in the final product, ranging between 0.2 and 1 percent of the total bacterial population. Subsequent rounds of fermentation using passive back-slopping without the addition of new L. rhamnosus led to a loss of this strain from the community of fermenting bacteria. Our results suggest that the addition of probiotic strains at every fermentation cycle can enrich the existing complex communities of traditionally fermented lait caillé while traditional bacterial strains remain dominant in the bacterial communities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / metabolism*
  • Biofilms
  • Cultured Milk Products / microbiology*
  • Fermentation*
  • Food Microbiology*
  • Probiotics / metabolism
  • Senegal
  • Yogurt / microbiology

Grant support

This work was funded by Bill & Melinda Gates Foundation [OPP1110874,] received by MEP; NWO WOTRO Global Challenges Programme [W08.250.2013.108,] received by SES; and Marie Curie International Outgoing Fellowships [328888,] received by SES. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.