Microbial Interactions in the Yoghurt Consortium: Current Status and Product Implications

Abstract

The metabolic potential of the fermenting microbial culture influences the characteristics of fermented products, but the extent to which this occurs depends on environmental factors and the microorganism’s interactions with its environment. It is therefore not possible to simply translate gene content to product characteristics and this is particularly the case when cultures are consortia of microorganisms influencing each other. The yoghurt consortium, consisting of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, is mainly characterized by mutualistic interactions between the two species. This review provides an updated overview of these interactions, based on the latest insights, and their impact on fermentation and product characteristics. Finally, some leads are given on how to use modulation of interactions as means to alter product characteristics.