The species Leuconostoc gasicomitatum was first described by Björkroth et al. (2000) in the late 1990s as a cause of premature spoilage of modified-atmosphere packaged (MAP) marinated broiler meat strips. The spoiled packages showed large accumulation of gas, and microbiological examination of the product revealed high numbers (>10⁹ cfu g⁻¹) of lactic acid bacteria, identified mainly as L. gasicomitatum. Since then, similar types of spoilage have been detected in many MAP raw beef, pork and poultry products (Vihavainen and Björkroth, 2007; Vihavainen and Björkroth, unpublished observations). In most cases, L. gasicomitatum together with Leuconostoc gelidum, another meat-associated Leuconostoc species, have been found to dominate the microbial spoilage populations. Although often present in very low numbers in the initial microbial population of meat, these organisms multiply during refrigerated storage and modified-atmosphere packaging conditions. In addition to meat and poultry, these organisms can grow rapidly and produce defects in other refrigerated, packaged, nutrition-rich food commodities. L. gasicomitatum and L. gelidum have been identified as spoilage organisms of an acetic acid fish product, with strong slime and gas formation being the main defects detected after a few weeks’ refrigerated storage (Lyhs et al., 2004). In this case, carrot slices added to fish marinade as garnish were considered the probable source of leuconostoc contamination. L. gasicomitatum and L. gelidum have also been involved in spoilage of cooked, vacuum-packaged vegetable sausages, causing accumulation of gas and slime and an acetic off-odour in the package (Vihavainen et al., 2008).