Microbial stability and safety of traditional Greek Graviera cheese: characterization of the lactic acid bacterial flora and culture-independent detection of bacteriocin genes in the ripened cheeses and their microbial consortia.

The microflora of four batches of traditional Greek Graviera cheese was studied at 5 weeks of ripening, and 200 lactic acid bacteria (LAB) isolates were phenotypically characterized and screened for antilisterial bacteriocins. The cheeses were also analyzed for organic acids by high-performance liquid chromatography and for the potential presence of 25 known LAB bacteriocin genes directly in cheese and their microbial consortia by PCR. All batches were safe according to the European Union regulatory criteria for Listeria monocytogenes, Salmonella, enterobacteria, and coagulase-positive staphylococci.

Use of artificial neural networks and a gamma-concept-based approach to model growth of and bacteriocin production by Streptococcus macedonicus ACA-DC 198 under simulated conditions of Kasseri cheese production.

Growth of and bacteriocin production by Streptococcus macedonicus ACA-DC 198 were assessed and modeled under conditions simulating Kasseri cheese production. Controlled fermentations were performed in milk supplemented with yeast extract at different combinations of temperature (25, 40, and 55 degrees C), constant pH (pHs 5 and 6), and added NaCl (at concentrations of 0, 2, and 4%, wt/vol). The data obtained were used to construct two types of predictive models, namely, a modeling approach based on the gamma concept, as well as a model based on artificial neural networks (ANNs).

Macedocin, a food-grade lantibiotic produced by Streptococcus macedonicus ACA-DC 198.

Streptococcus macedonicus ACA-DC 198, a strain isolated from Greek Kasseri cheese, produces a food-grade lantibiotic named macedocin. Macedocin has a molecular mass of 2,794.76 +/- 0.

Bacteriocin production by Enterococcus faecium FAIR-E 198 in view of its application as adjunct starter in Greek Feta cheese making.

Bacteriocin production by Enterococcus faecium FAIR-E 198, isolated from Greek Feta cheese, was studied in batch fermentations, under conditions simulating Feta cheese preparation. Maximum enterocin activity and growth rate was obtained in de Man-Rogosa-Sharpe (MRS) broth at 37 degrees C with controlled pH 6.5.