The dynamics of growth, survival and biochemical activity of microorganisms in food are the result of stress reactions in response to the changing of the physical and chemical conditions into the food microenvironment, the ability to colonise the food matrix and to growth into a spatial heterogeneity, and the in situ cell-to-cell ecological interactions which often happen in a solid phase. In food, ecological approaches to study the evolution of microbial flora would be useful to comprehend better the microbiological processes involved in food processing and ripening, to improve microbiological safety by monitoring in situ pathogenic bacteria, and to evaluate the effective compositions of the microbial populations. This paper gives a general overview of biotechnological approaches to study microbial populations in food fermentation.