Functional genomics for food microbiology: Molecular mechanisms of weak organic acid preservative adaptation in yeast

The recent era of genomics has offered tremendous possibilities to biology. This concise review describes the possibilities of applying (functional) genomics studies to the field of microbial food stability. In doing so, the studies on weak-organic-acid stress response in yeast are discussed by way of an example. We outline briefly what weak organic acids are and what the classical view is with respect to their antimicrobial effect. Next, the players in resistance development are described. We then come to the identification of the missing links and discuss how the current genomics-driven data acquisition can aid in gathering pieces of the puzzle. Recently established genome-wide data analysis tools are discussed and we illustrate how one can go from an inventory-oriented approach to a functional analysis of the obtained lists of present, induced and repressed genes. Finally, we present a 'genomics updated' version of the current concept of the mode of action of weak-acid preservatives and the inferred cellular responses. Evidently, any relevant continuous (preservation) stress imposed on microbial cells may be analysed with a similar approach, making the discussion and conclusions more broadly applicable.