Pediococcus

Pediococcus is a genus of Gram-positive, non-spore-forming lactic acid bacteria that typically occur as cocci arranged in pairs or short chains or tetrads. Members are facultative anaerobes and are part of the lactic acid bacteria group within the order Lactobacillales and the family Pediococcaceae. They ferment sugars to lactic acid, often with a high tolerance for salt and low pH, making them well suited to food environments such as dairy, meat, and fermented vegetables.

Ecology and use: Pediococcus species are widespread in plant materials and are common inhabitants of many fermented foods. In meat and vegetable fermentations they contribute acidity and flavor development. Several species are used as starter cultures or adjuncts in fermentation processes, notably Pediococcus pentosaceus and Pediococcus acidilactici. Some strains are also marketed as probiotics for animals or humans.

Safety and spoilage: While many strains are regarded as safe for use in foods, some species can cause spoilage in beer, wine, and other beverages, producing ropy textures or diacetyl and acetoin, which degrade product quality. P. damnosus and related species are particularly associated with beer spoilage, whereas other species can act as contaminants.

Notable species: P. pentosaceus, P. acidilactici, P. damnosus, P. claussenii, P. parvulus.