Technical Abstract: Preservation of vegetables by fermentation is one of the earliest and most widespread technologies developed by man. Fermented and acidified vegetable products are produced and consumed in every culture and society around the world, usually based on traditional processing methods. This is because the products produced are safe even in the absence of refrigerated storage, due to the inhibitory metabolites produced primarily by lactic acid bacteria. Lactic acid bacteria may also be used to control spoilage of fresh vegetable products. The factors influencing microbial competition during fermentation or spoilage of fresh vegetable products have proved to be difficult to understand, but biocontrol strategies have the potential to ensure the safety and control the microbial ecology of food spoilage for many types of non-fermented foods. Significant challenges remain, however, in understanding the mode of action of organic acids in killing bacterial pathogens, and how those pathogens respond and adapt to acid challenge.