Propionibacterium freudenreichii

Propionibacterium freudenreichii
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Actinomycetota
Class: Actinomycetia
Order: Propionibacteriales
Family: Propionibacteriaceae
Genus: Propionibacterium
Species:
P. freudenreichii
Binomial name
Propionibacterium freudenreichii
van Niel 1928 (Approved Lists 1980)[1]
Type strain
ATCC 6207
CCUG 7433
CIP 103026
DSM 20271
HAMBI 274
IFO 12424
LMG 16412
NBRC 12424
NCTC 10470
NRRL B-3523
Synonyms
  • Propionibacterium freudenreichii subsp. shermanii (van Niel 1928) Holdeman and Moore 1970 (Approved Lists 1980)
  • "Propionibacterium shermanii" van Niel 1928

Propionibacterium freudenreichii is a gram-positive, non-motile bacterium that plays an important role in the creation of Emmental cheese, and to some extent, Jarlsberg cheese, Leerdammer and Maasdam cheese. Its concentration in Swiss-type cheeses is higher than in any other cheese. Propionibacteria are commonly found in milk and dairy products, though they have also been extracted from soil. P. freudenreichii has a circular chromosome about 2.5 Mb long. When Emmental cheese is being produced, P. freudenreichii ferments lactate to form acetate, propionate, and carbon dioxide

(3 C3H6O3 → 2 C2H5CO2 + C2H3O2 + CO2).[2]

The products of this fermentation contribute to the nutty and sweet flavors of the cheese, and the carbon dioxide byproduct is responsible for forming the holes, or "eyes" in the cheese. Cheesemakers control the size of the holes by changing the acidity, temperature, and curing time of the mixture. An estimated one billion living cells of P. freudenreichii are present in one gram of Emmental. In contrast to most lactic acid bacteria, this bacterium mainly breaks down lipids, forming free fatty acids. Recent research has focused on possible benefits incurred from consuming P. freudenreichii, which are thought to cleanse the gastrointestinal tract.[3] P. freudenreichii has also been suggested to possibly lower the incidence of colon cancer.[4][5] This mutualistic relationship is unusual in propionibacteria, which are largely commensal.

The performance and growth of P. freudenreichii is highly dependent on the presence of Lactobacillus helveticus, which provides essential amino acids. The degradation of L. helvecticus releases a variety of amino acids and peptides. While P. freudenreichii has been found to grow even in the absence of L. helvecticus, some strains of the bacteria were observed lysing in the absence of glutamine, lysine, or tyrosine.[6] The autolysis of P. freudenreichii has been suggested to contribute further to the flavor of the Emmental cheese. The conditions leading to the autolysis of this bacterium are not well known.[7]

  1. ^ Van N. (1928). The propionic acid bacteria. Haarlem, Holland: Uitgeverszaak and Boissevain and Co.
  2. ^ "A bacterium used in the production of Emmental". Genoscope. 16 January 2008. Archived from the original on 9 February 2008.
  3. ^ Cousin FJ, Mater DD, Foligne B, Jan G (2 August 2010). "Dairy propionibacteria as human probiotics: A review of recent evidence" (PDF). Dairy Science & Technology. 91 (1): 1–26. doi:10.1051/dst/2010032. S2CID 6044008.
  4. ^ Jan G, Belzacq AS, Haouzi D, Rouault A, Métivier D, Kroemer G, Brenner C (February 2002). "Propionibacteria induce apoptosis of colorectal carcinoma cells via short-chain fatty acids acting on mitochondria". Cell Death and Differentiation. 9 (2): 179–88. doi:10.1038/sj/cdd/4400935. PMID 11840168.
  5. ^ Lan A, Bruneau A, Bensaada M, Philippe C, Bellaud P, Rabot S, Jan G (December 2008). "Increased induction of apoptosis by Propionibacterium freudenreichii TL133 in colonic mucosal crypts of human microbiota-associated rats treated with 1,2-dimethylhydrazine". The British Journal of Nutrition. 100 (6): 1251–9. doi:10.1017/S0007114508978284. PMID 18466653.
  6. ^ McCarthy RJ. "Amino acid requirements of dairy Propionibacterium strains". Ohio State University. Archived from the original on 2009-02-15. Retrieved 2008-11-11.
  7. ^ Ostlie H (1995). "Autolysis of Dairy Propionibacteria: Growth Studies, Peptidase Activities, and Proline Production". Journal of Dairy Science. 78 (6): 1224–1237. doi:10.3168/jds.S0022-0302(95)76742-X.