Acid bacteriocin production

De Vuyst L and Leroy F. 2007. Bacteriocins from lactic acid bacteria production, purification, and food applications. J Mol Microbiol Biotechnol 13 194-199. 

LAB can synthesise compounds with metabolic activity such as H2O2, organic acids and bacteriocins. Several smdies have been conducted on bacteriocin production ... 

Navarro, L., Zarazaga, M., Saenz, 1., Ruiz-Larrea, R, Torres, C. (2000). Bacteriocin production by lactic acid bacteria isolated from Rioja red wines. J. Appl. Microbiol, 88, 41-51. 

Stiles, M.E. and Hastings, J.W. 1991. Bacteriocin production by lactic acid bacteria Potential for use in meat preservation. Trends Food Sci. Technol. 2, 247-251. 

Allende, A., Martinez, B., Selma, V., Gil, M.I., Suarez, J.E., and Rodriguez, A. 2007. Growth and bacteriocin production by lactic acid bacteria in vegetable broth and their effectiveness at reducing Listeria monocytogenes in vitro and in fresh-cut lettuce. Food Microbiology 24 759-766. 

Silva, J., Carvalho, A.S., Teixeira, R, and Gibbs, P.A. Bacteriocin production by spray-dried lactic acid bacteria, Lett. Appl. Microbiol, 34, 77, 2002. 

There are many scientific evidences, supported by clinical studies, on the efficacy of probiotics in the prevention and treatment of gastrointestinal disorders, respiratory, and urogenital diseases. Many microbial strains with probiotic properties are able not only to restore the intestinal microbial balance, but also to impart other beneficial effects on health, associated with the production of acids, bacteriocins and with the competition with pathogenic microorganisms. Among these, the main effects are the reduction of the level of cholesterol in the blood, the reduction of fecal enzymes, with potentially mutagenic activity that can induce the onset of tumors, the reduction of lactose intolerance, the increase of the response of the immune system, the increase of calcium absorption, and synthesis of vitamins. ... 

Pseudomonas, Escherichia coli, Staphylococcus aureus and Yersinia entero-colitica. In fermented products, diacetyl is normally produced in very low concentrations (<10 ppm) however, in combination with other factors, e.g. the presence of organic acid, bacteriocins, H2O2 and nutrient depletion, the total inhibitory effect may be substantial. 

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. 

Sezer, G., Giiven, A. (2009). Investigation of bacteriocin production capability of lactic acid bacteria isolated from foods. Lafkas Univ Vet Fak Derg, 15,45-50. 

Birri, D.J., Brede, D.A., Tessema, G.T., and Nes, I.F. (2013). Bacteriocin production, antibiotic susceptibility and prevalence of haemolytic and gelatinase activity in faecal lactic acid bacteria isolated from healthy Ethiopian infants. Microl) coZ 65, 504-516. 

LAB also interact among themselves. Some Pediococcus and Lactobacillus strains were shown to be inhibitors of other lactobacilli and more often of Leuc. mesenteroides and O. oeni also Lact. plantarum seems to be capable of inhibiting O. oeni. Bacteriocin production as well as the presence of sequences of the bacteriocin pin locus were established in inhibitory strains (Navarro et al. 2000 Knoll et al. 2008). In contrast, mutualism was demonstrated between a strain of Pediococcus pentosaceus and one of O. oeni. The high proteolytic activity of the O. oeni released essential amino acids for the P. pentosaceus strain (Fernandez and de Nadra 2006). All these phenomena are very complex involving a huge variety of strains that represent each of the species simultaneously present in the wine. 

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). 

The primary starter performs several functions in addition to acid production, especially reduction of the redox potential ( h, from about + 250 mV in milk to —150 mV in cheese), and, most importantly, plays a major, probably essential, role in the biochemistry of cheese ripening. Many strains produce bacteriocins which control the growth of contaminating micro-organisms. 

Properly made cheese is quite a hostile environment for bacteria due to a low pH, moderate-to-high salt in the moisture phase, anaerobic conditions (except at the surface), lack of a fermentable carbohydrate and the production of bacteriocins by the starter. Consequently, cheese is a very selective environment and its internal non-starter microflora is dominated by lactic acid bacteria, especially mesophilic lactobacilli, and perhaps some Micrococcus and Pediococcus. 

The effects of dietary FOS on the GI microflora of poultry are well documented. Flidaka et ol. (1991) found that consumption of 8 g FOS per day increased numbers of bifidobacteria, improved blood lipid profiles and suppressed putrefactive substances in the intestine. Patterson et d. (1997) found that caecal bifidobacteria concentrations increased 24-fold and lactobacilli populations increased 7-fold in young broilers with FOS. Bifidobacteria may inhibit other microbes because of a high production of volatile fatty acids (VFAs) or the secretion of bacteriocin-like peptides (Burel and Valat, 2007). The improvement in gut health status by dietary FOS supplementation often results in improved growth performance. Ammerman et d. (1988) demonstrated that the addition of dietary FOS at a level of 2.5 or 5.0g/kg diet improved feed efficiency over the period from 1 to 46 days of age. Mortality was reduced with the higher level. However, Waldroup et d. (1993) found that supplementing the diet of broilers with 3.75 g/kg FOS had few consistent effects on production parameters or carcass Sdmonella concentrations. 

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