First Evidence of Lysogeny in Propionibacterium freudenreichii subsp. shermanii

Abstract

Dairy propionic acid bacteria, particularly the species Propionibacterium freudenreichii, play a major role in the ripening of Swiss type cheese. Isometric and filamentous bacteriophages infecting P. freudenreichii have previously been isolated from cheese. In order to determine the origin of these bacteriophages, lysogeny of P. freudenreichii was determined by isometric bacteriophage type analysis. The genomic DNA of 76 strains were hybridized with the DNA of nine bacteriophages isolated from Swiss type cheeses, and the DNA of 25 strains exhibited strong hybridization. Three of these strains released bacteriophage particules following UV irradiation (254 nm) or treatment with low concentrations of mitomycin C. A prophage-cured derivative of P. freudenreichii was readily isolated and subsequently relysogenized. Lysogeny was therefore formally demonstrated in P. freudenreichii.Based on habitat, the genus Propionibacterium can be divided into two groups: cutaneous and dairy (or classic) propionic acid bacteria (dairy PAB). Dairy PAB are gram-positive, non-spore-forming, catalase-positive, nonmotile, facultatively anaerobic organisms (18). They are used in the manufacture of Swiss type cheeses to ensure eye formation and the development of a typical flavor (19).Like members of many other bacterial genera, dairy PAB are infected by viruses (14). Two types of bacteriophages which can infect dairy PAB have been isolated in Swiss type cheeses. One type belongs to group B1 of Bradley's classification, and the other is, to our knowledge, the first infective filamentous virus found in gram-positive bacteria (16). The existence of bacteriophage DNA able to replicate and express itself in the genus Propionibacterium enabled us to determine the efficiency of electrotransfection for developing a cloning vector (13).The isometric type of bacteriophages that infect dairy PAB have frequently been shown to be present in Swiss type cheeses; the levels of contamination range from 14 to 7 ϫ 10 5 PFU/g of cheese, depending on the cheese and the indicator strain used for detection. These bacteriophages are produced during multiplication of dairy PAB during cheese ripening and may multiply on either endogenous or starter strains (15). In order to understand and control the multiplication of bacteriophages during cheese production, it is important to determine their source in the manufacturing plant. We have shown that raw milk can be a source of free bacteriophages (15), although lysogenic strains may also produce them.Lysogeny is widespread in nature, but in the context of the genus Propionibacterium, only lysogeny of Propionibacterium acnes has been studied previously (33,35).The purpose of this work was to demonstrate lysogeny of dairy PAB. Studies of putative lysogeny are hindered by problems with finding the lysogen and sensitive strains. It is also difficult to determine the optimum amount of mutagenic agent and the optimum bacterial growth stage for massive prophage induction. There is some homology between the virulent and temp...

Production of cheese flavour compounds derived from amino acid catabolism by Propionibacterium freudenreichii

“…g -1 in the inoculated cheeses, whereas indigenous PAB remained under 5 × 10 6 cfu . g -1 at the end of ripening in control ones [25]. Several volatile branchedchain compounds were found at a significantly higher level in the presence of PAB: 3-methylbutanol, 2-methylbutanol, 2-methylbutanal, two branched-chain esters and isovaleric acid (Tab.…”

Bacteriophages InfectingPropionibacterium acnes

“…freudenreichii , P. freudenreichii subsp. shermanii , Propionibacterium jensenii, and Propionibacterium thoenii ); Southern blot-based detection and induction by either mitomycin C or UV were used to confirm their presence and functionality [58]. Furthermore, phages infecting P. acnes have all been classified as dsDNA carrying siphoviruses; in contrast, P. freudenreichii can also be infected by ssDNA filamentous phages [25].…”

Production of tetrapyrrole compounds and vitamin B12 using genetically engineering of Propionibacterium freudenreichii. An overview

“…DNA restriction/modification systems observed in propionibacteria have to be taken into account since successful DNA transformation at high rates (up to 10 8 transformants·µg -1 DNA) succeeds only with plasmid DNA originating from propionibacteria with the same restriction/modification system(s) as the strain to be transformed, and not from E. coli hosts. Furthermore, the basis for an integrating vector has been set up after identification of a potential attP site and an adjacent integrase gene from a Propionibacterium phage/ prophage system [16]. Kiatpapan et al [30] succeeded in overexpression of heterologous genes in propionibacteria, such as choA encoding cholesterol oxidase from Streptomyces [39] and hemA encoding 5-aminolevulinic acid (ALA) synthase from Rhodobacter sphaeroides [41] based on pPK705 and screened endogenous promoters.…”