LAB and biopreservation

Lactic acid bacteria and bifidobacteria are preferred as protective and probiotic cultures, and have been used since the beginning of history as starter cultures. They have a long history of being safely used and consumed. LAB are widely used for fermentation of milk, meat, and vegetable foods. In fermentation of dairy products, lactose is metabolized to lactic acid. Other metabolic products, hydrogen peroxide, diacetyl, and bacteriocins may also play inhibitory roles and contribute to improving the organoleptic attributes of these foods, as well as their preservation (Messens and De Vuyst, 2002). 

LAB include the genera Lactococcus, Streptococcus, Pediococcus, Leuconostoc, Enterococcus, Carnobacterium, and Propionibacterium, and a wide variety of strains are routinely used as starter cultures in manufacturing dairy, meat, and vegetable products (O Sullivan, Ross, and Hill, 

Organic acids (lactic, acetic) Bacteriocins co2 Hydrogen peroxide Diacetyl Reuterin Ethanol Increase acidity, antimicrobial compounds Nisin only bacteriocin permitted as food preservative, disrupts cytoplasmic membrane Reduces membrane permeability Oxidizes proteins Interacts with arginine-binding proteins Not confirmed, may interact with thiol group in proteins that may lead to oxidative stress (Whitehead et al., 2008) 

Source Adams, M.R. Microbiology of Fermented Food, pp. 1 4. London Blackie Academic and Professional, 1998.  

Low redox potential Nutrient depletion Crowding pH reduction of surrounding medium (pH 3.5-4.5) Growth decreases carbohydrate food content Competitive growth inhibits spoilage or pathogenic organisms 

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