Because of the central role of fermentation in food production and preparation, microorganisms are constantly encountered in these processes. ME can rationally improve the properties of these microorganisms and their efficiency for producing different products. Bacteria occupy a central place among these microorganisms, as either the bacteria per se (e.g., as starter cultures and probiotics) or products synthesized by bacteria (i.e., used as biocatalyst in the synthesis of amino acids, organic acids, vitamins, and carbohydrates). This illustrates the tremendous potential of ME for improving the bacteria used by the food industry.