Propionibacterium

Propionibacterium is a gram-positive, anaerobic, rod-shaped genus of bacteria named for their unique metabolism: They are able to synthesize propionic acid by using unusual transcarboxylase enzymes.<ref>Cheung, Y.F., Fung, C., and Walsh, C. "Stereochemistry of propionyl-coenzyme A and pyruvate carboxylations catalyzed by transcarboxylase." 1975. Biochemistry 14(13), pg 2981.</ref>

Its members are primarily facultative parasites and commensals of humans and other animals, living in and around the sweat glands, sebaceous glands, and other areas of the skin. They are virtually ubiquitous and do not cause problems for most people, but propionibacteria have been implicated in acne and other skin conditions.<ref>Bojar, R., and Holland, K. "Acne and propionibacterium acnes." 2004. Clinics in Dermatology 22(5), pg. 375-379.</ref> One study found the Propionibacterium was the most prevalent human skin-associated genus of microorganisms.<ref name=Rust>Template:Cite news</ref>

In ruminants, propionibacteria reduce nitrate to nontoxic nitrogen compounds.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Members of the genus Propionibacterium are widely used in the production of vitamin B₁₂, tetrapyrrole compounds, and propionic acid, as well as in the probiotics and cheese industries.<ref>Kiatpapan P., Murooka Y. Genetic manipulation system in propionibacteria. Journal of Bioscience and Bioengineering. 93 (1) (pp 1–8), 2002</ref>

The strain Propionibacterium freudenreichii subsp. shermanii is used in cheesemaking to create CO₂ bubbles that become "eyes"—round holes in the cheese.<ref>Making Swiss Cheese - David B. Fankhauser, Ph.D.</ref>

Pathology

Propionibacterium spp. are commensal bacteria that can occasionally cause infectious diseases. The most studied of these infections is acne vulgaris, caused by Cutibacterium acnes (formerly Propionibacterium acnes).<ref>Template:Cite journal</ref> It is a chronic inflammatory disease caused by the blockage of pilosebaceous units causing inflammatory lesions, non-inflammatory lesions or a mixture of both on the face, neck and/or chest.<ref name=":0">Template:Cite book</ref><ref>Template:Cite journal</ref> Acne vulgaris cannot be defined as an infectious disease since the bacteria is found on a vast majority of individuals without causing lesions.<ref name=":0" /> C. acnes colonize the skin only under certain favorable conditions. In most cases, C. acnes get trapped under the comedones where they proliferate to form micro-comedones, not visible to the naked eye,<ref>Template:Cite book</ref> which can later form structures such as closed comedones (white heads) and open comedones.<ref name=":0" /> These comedones can rupture, releasing the follicular material inside the dermis. The cause of this rupture was thought to be the indirect effect of fat metabolism by the bacteria, however it was later found that bacteria are directly involved in comedome rupturing by producing factors such as proteases, hyaluronidases and neuraminidases which might be involved in thinning of the epithelium.<ref>Template:Cite journal</ref> C. acnes can also produce immune factors such as proinflammatory cytokine inducing-factors<ref>Template:Cite journal</ref> and chemotactic factors,<ref>Template:Cite journal</ref> and can induce host complement pathways.<ref>Template:Cite journal</ref>

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)<ref name=LPSN>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and National Center for Biotechnology Information (NCBI).<ref name=NCBI>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

16S rRNA based LTP_10_2024<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	120 marker proteins based GTDB 09-RS220<ref name="about">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref><ref name="tree">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref><ref name="taxon_history">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>

See also

• List of bacterial orders
• List of bacteria genera