Occurrence of Propionibacterium freudenreichii bacteriophages in swiss cheese

Occurrence of Propionibacterium freudenreichii bacteriophages in swiss cheese.

We isolated bacteriophages active against Propionibacterium freudenreichii from 16 of 32 swiss cheese samples. Bacteriophage concentrations ranged from 14 to 7 x 10(5) PFU/g, depending on the sample and the sensitive strain used for detection. Only a few strains, 8 of the 44 strains of P. freudenreichii in our collection, were sensitive. We observed that multiplication of bacteriophages occurre...

Emmental Cheese Environment Enhances Propionibacterium freudenreichii Stress Tolerance

Dairy propionibacteria are actinomycetales found in various fermented food products. The main species, Propionibacterium freudenreichii, is generally recognized as safe and used both as probiotic and as cheese starter. Its probiotic efficacy tightly depends on its tolerance towards digestive stresses, which can be largely modulated by the ingested delivery vehicle. Indeed, tolerance of this bac...

Lipase and Esterase Activities of Propionibacterium freudenreichii subsp. freudenreichii.

The lipase and esterase activities of eight strains of dairy Propionibacterium freudenreichii subsp. freudenreichii were studied. A lipase activity was detected on whole cells and in the culture supernatant. The highest activity was expressed at 45 degrees C and pH 6.8. An esterase activity was also detected in the culture medium. The electrophoresis of the intracellular fractions of the cells ...

The secreted esterase of Propionibacterium freudenreichii has a major role in cheese lipolysis.

Free fatty acids are important flavor compounds in cheese. Propionibacterium freudenreichii is the main agent of their release through lipolysis in Swiss cheese. Our aim was to identify the esterase(s) involved in lipolysis by P. freudenreichii. We targeted two previously identified esterases: one secreted esterase, PF#279, and one putative cell wall-anchored esterase, PF#774. To evaluate their...

Utilization of coenzyme A by Propionibacterium freudenreichii.