Bacteriocins dairy products

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Aslim, B., Yuksekdag, Z.N., Sarikaya, E., and Beyatli, Y. 2005. Determination of the bacteriocin-like substances produced by some lactic acid bacteria isolated from Turkish dairy products. Swiss Society of Food Science and Technology 38 691-694. 

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). 

Sobrino-Lopez, A. and Martm-Belloso, O. 2008. Use of nisin and other bacteriocins for preservation of dairy products. International Dairy Journal 18 329-343. 

Pediocin Pediocin is a cationic membrane-permeabilizing antimicrobial peptide of Class Ila. The best-known pediocin is pediocin PA-l/AcH, which is a small antilisterial plasmid-encoded peptide produced by P. acidilactici. Pediocins are commercially traded as bacteriocin-containing fermentative powder by companies such as Kerry Bio-Sciences, Chr. Hansen, and Handary [52, 53] (Table 11.2). Other species such as P. pentosaceus and P. parvulus and strains belonging to Lb. plantarum are also capable of producing this compound [62, 63]. Although pediocin is mainly used in meat products, its production in heterologous hosts is considered an attractive alternative in dairy products [52,141] (Table 11.3). 

Ferchichi, M., Frde, J., Mabrouk, K., and Manai, M. (2001) Lactococcin MMFll, a novel class 11a bacteriocin produced by Lactococcus lactis MMFll, isolated from a Tunisian dairy product. FEMS Microbiol Lett 205,49-55. 

Numerous bacteriocins are produced by lactic acid bacteria (Klaenhammer, 1988), but only a few bacteriocins have been found in propionibacteria (Lyon and Glatz, 1991, 1993 Giinstead and Barefoot, 1992). Recently, 14 dairy propionibacteria were screened for catalase-insentitive, protease-sensitive inhibition of Gram-positive and Gramnegative bacteria (Ratnam et al., 1998). Bacteriocin production was identified in 57% of these cultures. 

Pai SL and Glatz BA (1987) Production, regeneration, and transformation of protoplasts of propionibacteiium strains. J Dairy Sci 70 (Suppl 1) 80 Paik H-D and Glatz BA (1995) Purification and partial amino acid sequence of propionicin PLG-1, a bacteriocin produced by Propionibacterium thoenii P127. Lait 75 ... 

There are a few examples where bacteriocins and bacteriocin-producing bacteria are presently in use. Mastitis is a bacterial infection of the mammary gland and udder tissue of dairy cattle and is usually treated with antibiotics. For years nisin A has been used in prophylactic treatment of and protection against mastitis. SevCTal commercial nisin-based products are presently on the market and these include products under the labels MastPro , Mast Out , Wipe Out , Consept , Nisin Z SUver-Elephant , and othCTS. 

---