''Penicillium glaucum'' is a

mold A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...

that is used in the making of some types of blue cheese, including

Bleu de Gex ''Bleu de Gex'' (also ''Bleu du Haut-Jura'' or ''Bleu de Septmoncel'') is a creamy, semi-soft blue cheese made from unpasteurized milk in the Jura region of France. It is named after the Pays de Gex, a historical region in what is now France a ...

Rochebaron Rochebaron is a soft blue cheese made from pasteurised cow's milk, in the town of Beauzac in the Auvergne region, in the Massif Central, France. This cheese is one of several that are made by curdling milk and separating the curds from the whey. ...

, and some varieties of

Bleu d'Auvergne Bleu d'Auvergne () is a French blue cheese, named for its place of origin in the Auvergne region of south-central France. It is made from cow's milk, and is one of the cheeses granted the Appellation d'origine contrôlée from the French govern ...

and

Gorgonzola Gorgonzola (; ) is a veined blue cheese, originally from Italy, made from unskimmed cow's milk. It can be buttery or firm, crumbly and quite salty, with a "bite" from its blue veining. History Historically, gorgonzola has been produced for ...

. (Other blue cheeses, including

Bleu de Bresse Bleu de Bresse () is a blue cheese that was first made in the Bresse area of France following World War II. Made from whole milk, it has a firm, edible coating which is characteristically white in color and has an aroma of mushrooms. Its creamy ...

Bleu du Vercors-Sassenage Bleu du Vercors-Sassenage is a mild pasteurized natural rind cow's milk blue cheese originally produced by monks in the Rhône-Alpes region of France in the 14th century. Now made in the Dauphiné area, the cheese has been a protected Appellation d ...

, Brebiblu,

Cambozola Cambozola is a cow's milk cheese that is a combination in style of a French soft-ripened triple cream cheese and Italian Gorgonzola. History Cambozola was patented and industrially produced for the world market by the large German company H ...

Cashel Blue ''J&L Grubb'' is an List of Irish cheeses, Irish cheese manufacturer, making cows' milk and goats' milk cheeses on their farm near Fethard, South Tipperary. History In 1984, the Grubbs began to make around eight Cashel Blue cheeses at their farm ...

Danish blue Danablu, often marketed under the trademark Danish Blue Cheese within North America, is a strong, blue-veined cheese. This semi-soft creamery cheese is typically drum- or block-shaped and has a yellowish, slightly moist, edible rind. Made from f ...

Fourme d'Ambert Fourme d'Ambert is a semi-hard French blue cheese. One of France's oldest cheeses, it dates from as far back as Roman times. It is made from raw cow's milk from the Auvergne region of France, with a distinct, narrow cylindrical shape. The semi-h ...

, Fourme de Montbrison, Lanark Blue,

Roquefort Roquefort is a sheep milk cheese from Southern France, and is one of the world's best known blue cheeses. Though similar cheeses are produced elsewhere, EU law dictates that only those cheeses aged in the natural Combalou caves of Roquefort-sur ...

, Shropshire Blue, and

Stilton Stilton is a village and civil parish in Cambridgeshire, England, about north of Huntingdon in Huntingdonshire, which is a non-metropolitan district of Cambridgeshire as well as a historic county of England. History There is evidence of Neo ...

use ''

Penicillium roqueforti ''Penicillium roqueforti'' is a common saprotrophic fungus in the genus ''Penicillium''. Widespread in nature, it can be isolated from soil, decaying organic matter, and plants. The major industrial use of this fungus is the production of blue ...

''.) In 1874, Sir William Roberts, a physician from

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

, noted that cultures of the mold did not display bacterial contamination.

Louis Pasteur Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...

would build on this discovery, noting that ''

Bacillus anthracis ''Bacillus anthracis'' is a gram-positive and rod-shaped bacterium that causes anthrax, a deadly disease to livestock and, occasionally, to humans. It is the only permanent ( obligate) pathogen within the genus ''Bacillus''. Its infection is a ...

'' would not grow in the presence of the related mold ''

Penicillium notatum ''Penicillium chrysogenum'' (formerly known as ''Penicillium notatum'') is a species of fungus in the genus ''Penicillium''. It is common in temperate and subtropical regions and can be found on salted food products, but it is mostly found in in ...

''. Its antibiotic powers were independently discovered and tested on animals by French physician

Ernest Duchesne Ernest Duchesne (30 May 1874 – 12 April 1912) was a French physician who noted that certain molds kill bacteria. He made this discovery 32 years before Alexander Fleming discovered the antibiotic properties of penicillin, a substance der ...

,Duchesne 1897
Antagonism between molds and bacteria. An English translation by Michael Witty. Fort Myers, 2013. ASIN B00E0KRZ0E and B00DZVXPIK. but his thesis in 1897 was ignored by the

Pasteur Institute The Pasteur Institute (french: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccines f ...

. ''P. glaucum'' was found by Pasteur to feed on only one

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical ant ...

tartaric acid Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes, but also in bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally i ...

, L-(+)-tartaric acid, which makes its use the earliest example of

kinetic resolution In organic chemistry, kinetic resolution is a means of differentiating two enantiomers in a racemic mixture. In kinetic resolution, two enantiomers react with different reaction rates in a chemical reaction with a chiral catalyst or reagent, resul ...

References

glaucum Molds used in food production Taxa named by Johann Heinrich Friedrich Link {{Eurotiomycetes-stub