Fermentations dairy

Small amounts of hydrogen peroxide in raw milk can activate the lactoperoxidase-catalyzed oxidation of thiocyanate to produce a bacterial inhibitor (Hogg and Jago 1970). Inhibitory compounds resulting from oxygen metabolism can produce initially slow starter culture growth in industrial dairy fermentations if the milk has been excessively agitated. 

Leuconostoc Starter culture in dairy fermentation Antimicrobial activity by producing various bacteriocins... 

Probiotics also play a role in dairy fermentations to assist in the preservation of milk as a result of the production of lactic acid and other antimicrobial compounds. They have other functions as well, which are not involved with preservation or organic acids (Parvez et al., 2006). 

Enterococci have featured in dairy fermentations for decades and isolates with histories of safe usage are being promoted as probiotic cultures. A variety of probiotic supplements are available for human and veterinary use. These range from fermented milks to lyophylised forms, containing both single and multiple strains. Actually about 20% of probiotic preparations in the market contains strains of enterococci - which in 50% consist from E. faecium (Ewing and Haresign 1989 Eranz et al. 1999 Hamilton-Miller et al. 1996). 

Szczepankowska, A.K., Gorecki, R.K., Koiakowski, P., and Bardowski, J.K. (2013) Lactic acid bacteria resistance to bacteriophage and prevention techniques to lower phage contamination in dairy fermentation. Lactic Acid Bacteria - R D for Food, Health and Livestock Purposes (ed Marcelino Kongo), pp, 23-72, doi 10.5772/51541... 

Hubert, E. M., Raya, R. R., TaUUez, R, De Giori, G. S. (2000). Characterization of natural isolates of Lactobacillus strains to be used as starter cultures in dairy fermentation. International Journal of Food Microbiology, 59,19—27. 

Debaryomyces Pseudomycelia producing asporogenous yeast Dairy fermentations D. hansenii... 

Hayes, M., Ross, R.P., Fitzgerald, G.F., and Stanton, C. (2007) Putting microbes to work dairy fermentation, cell factories and bioactive peptides. Part 1 overview. Biotechnol J 2, 426-434. 

Starter cultures are continuously exposed to phage attack in food fermentations. Dairy fermentations are particularly susceptible to phage attack due to the rather limited starter culture repertoire and the use of non-sterile substrates such as milk. Moreover, in many dairy plants starter cultures are cultivated in large volumes and in rich media, which are ideal conditions for phage propagation. Therefore, strategies to avoid the presence and survival of phages in dairy factories have always been a matter of concern. 

In addition to LAB, some PAB species used in dairy fermentation are considered good probiotic candidates in human health (Cousin et al. 2012). Members of the PAB group were identified in the poultry GIT microbiota by culture-dependent (Salanitro et al. 1978) and culture-independent techniques (Apajalahti et al. 1998). Isolates of P. acidipropionici and P. avidum were recently tested for their probiotic potential in poultry. These PAB were shown to produce short chain fatty acids (SCFA) in an in vitro cecal model at concentrations high enough to inhibit S. enterica serovar Enteritidis. Moreover, P. acidipropionici strain LET 105 was also able to compete with Salmonella for adhesion sites on the intestinal mucosa in ex vivo assays (Arganaraz-Martinez et al. 2013). 

Lactic Acid Bacteria for Dairy Fermentations Specialized Starter Cultures to Improve Dairy Products... 

L. lactis and Strep, thermophilus are the most extensively used LAB species in dairy fermentative processes, thus several phages infecting them have been isolated and characterized in detail (Sudrez et al. 2002 Emond and Moineau 2007, Quiberoni et al. 2010). The extended co-survival of LAB and phages within the same environment has prompted the acquisition of a variety of native bacteriophage defense systems. These mechanisms include inhibition of phage adsorption, blocking of DNA injection, restriction/modification systems, abortive infection (Moineau and Levesque 2005), and the novel clustered interspaced short palindromic repeats (CRISPR) systems. 

Briggiler Marc6, M., Moineau, S., and Quiberoni, A. (2012) Bacteriophages and dairy fermentations. Review. Bacteriophage 2(3), 149-158. 

The in situ synthesis of EPS by LAB during milk fermentation improves the viscosity and texture of the fermented product, especially in stirred yogurts (Ruas-Madiedo and de los Reyes Gavildn 2005) since these biopol3mers act as thickeners and emulsifiers. Moreover, these EPS can be used as fat replacers in low-caloric (i.e., low-fat Mozzarella cheese) products (Hassan 2008). Although the effect of these compounds was firstly applied to dairy fermented foods, more recently EPS-producing... 

Smit, B.A., Engels, W.J.M., and Wouters, J.T.M. (2004) Diversity of L-leucine catabolism in various microorganisms involved in dairy fermentations, and identification of the rate-controlling step in the formation of the potent flavour component 3-methylbutanal. Appl Microbiol Biotechnol 64, 396-402. 

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