The role of cold-shock proteins in low-temperature adaptation of food-related bacteria

There is a considerable interest in the cold adaptation of food-related bac teria, including starter cultures for industrial food fermentations, food s poilage bacteria and food-borne pathogens. Mechanisms that permit low-tempe rature growth involve cellular modifications for maintaining membrane fluid ity, the uptake or synthesis of compatible solutes, the maintenance of the structural integrity of macromolecules and macromolecule assemblies, such a s ribosomes and other components that affect gene expression. A specific co ld response that is shared by nearly all food-related bacteria is the induc tion of the synthesis so-called cold-shock proteins (CSPs), which are small (7 kDa) proteins that are involved in mRNA folding, protein synthesis and/ or freeze protection. In addition, CSPs are able to bind RNA and it is beli eved that these proteins act as RNA chaperones, thereby reducing the increa sed secondary folding of RNA at low temperatures. In this review establishe d and novel aspects concerning the structure, function and control of these CSPs are discussed. A model for bacterial cold adaptation, with a central role for ribosomal functioning, and possible mechanisms for low-temperature sensing are discussed.