Charles Thom (November 11, 1872 – May 24, 1956) was an American

microbiologist A microbiologist (from Ancient Greek, Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of Microorganism, microscopic organisms such as bacteria, algae, f ...

and

mycologist Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...

. Born and raised in

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

, he received his PhD from the

University of Missouri The University of Missouri (Mizzou, MU, or Missouri) is a public university, public Land-grant university, land-grant research university in Columbia, Missouri. It is Missouri's largest university and the flagship of the four-campus Universit ...

, the first such degree awarded by that institution. He was best known for his work on the microbiology of dairy products and soil fungi, and in particular his research into the genera ''

Aspergillus ' () is a genus consisting of several hundred mold species found in various climates worldwide. ''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Miche ...

'' and ''

Penicillium ''Penicillium'' () is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production. Some members of the genus produce pe ...

''. His work influenced the establishment of standards for food handling and processing in the USA. He pioneered the use of

culture media A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss ''Physcomitrella patens''. Different ...

to grow microorganisms, and, with food chemist James N. Currie, developed a process to mass-produce

citric acid Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in t ...

using ''Aspergillus''. Thom played an important role in the development of

penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

Early life

Thom was born in Minonk, Illinois in 1872, the fifth of six boys. His parents were Angus Sutherland Thom and Louisa (Herick) Thom, Scottish/Irish farmers who had settled in Illinois shortly before the

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...

. Charles Thom was raised in a strongly religious household; his father was an elder in the

Presbyterian Presbyterianism is a part of the Reformed tradition within Protestantism that broke from the Roman Catholic Church in Scotland by John Knox, who was a priest at St. Giles Cathedral (Church of Scotland). Presbyterian churches derive their nam ...

church. Thom upheld Presbyterian values throughout his life, kept active in church affairs, and became a staunch

prohibition Prohibition is the act or practice of forbidding something by law; more particularly the term refers to the banning of the manufacture, storage (whether in barrels or in bottles), transportation, sale, possession, and consumption of alcoholic ...

ist. His early years spent working on his father's farm instilled the value of a strong work ethic, and first-hand knowledge of agricultural practices that would prove useful in his later career. After graduating from high school, Thom attended

Lake Forest Academy Lake Forest Academy (also known as LFA) is a co-educational college preparatory school for boarding and day students in grades 9 through 12. The school is located on the North Shore in Lake Forest, Illinois, United States, about 30 miles north o ...

, a preparatory institution for college, in 1889. He earned a

bachelor's degree A bachelor's degree (from Middle Latin ''baccalaureus'') or baccalaureate (from Modern Latin ''baccalaureatus'') is an undergraduate academic degree awarded by colleges and universities upon completion of a course of study lasting three to six ...

from

Lake Forest College Lake Forest College is a private liberal arts college in Lake Forest, Illinois. Founded in 1857 as Lind University by a group of Presbyterian ministers, the college has been coeducational since 1876 and an undergraduate-focused liberal arts inst ...

in 1895. The next year he spent as a science teacher in a Danville high school, before returning to Lake Forest College to receive his

Master's degree A master's degree (from Latin ) is an academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional practice.

in 1897. In 1899, working under the supervision of Howard Ayers, he received his PhD from the

on the topic of fertilization in the ferns ''

Aspidium ''Tectaria'' is a genus of fern in the family Tectariaceae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Halberd fern is a common name for species in this genus. Species , the ''Checklist of Ferns and Lycophyte ...

'' and ''

Adiantum ''Adiantum'' (), the maidenhair fern, is a genus of about 250 species of ferns in the subfamily Vittarioideae of the family Pteridaceae, though some researchers place it in its own family, Adiantaceae. The genus name comes from Greek, meaning "un ...

''. This was the first doctorate awarded by that institution. Thom married Ethel Winifred Slater in 1906, with whom he had three children (one died during childbirth). Ethel Thom died in October 1942, shortly before his retirement. In 1944 he remarried, to Charlotte J. Bayles, with whom he lived until her death. Thom died two years after Charlotte at his home in

Port Jefferson, New York Port Jefferson (informally known as "Port Jeff") is an incorporated village in the town of Brookhaven in Suffolk County, New York, on the North Shore of Long Island. Officially known as the Incorporated Village of Port Jefferson, the population ...

, on May 24, 1956.

Career

In 1902, Thom went to study with George F. Atkinson at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

; two colleagues included

Benjamin Duggar Benjamin Minge Duggar (September 1, 1872 – September 10, 1956) was an American plant physiologist.Makers of American Botany, Harry Baker Humphrey, Ronald Press Company, Library of Congress Card Number 61-18435 He was born at Gallion, Hale County ...

and

Herbert Hice Whetzel Herbert Hice Whetzel (September 5, 1877 – November 30, 1944) was an American plant pathologist and mycologist. As a Professor of Plant Pathology, he led the first department of Plant Pathology at an American university and founded the Cornell Pl ...

, who both later became noted botanists. Two years later, he accepted a position as dairy mycologist, working with Herbert William Conn, in charge of "cheese investigations" at the

Storrs Agricultural Experiment Station The Storrs, Connecticut, Storrs Agricultural Experiment Station (SAES) is an American agricultural experiment station operated by the University of Connecticut and founded in 1887. Part of UConn's College of Agriculture, Health, and Natural Resour ...

Connecticut Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its cap ...

. He remained in this institution—a branch of the

U.S. Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

(USDA)— holding various research and administrative positions, until his retirement in 1942. During his employment there, Thom investigated the process of

cheese ripening Cheese ripening, alternatively cheese maturation or affinage, is a process in cheesemaking. It is responsible for the distinct flavour of cheese, and through the modification of "''ripening agents''", determines the features that define many d ...

and sought to understand the composition of the microbiological flora required for imparting certain flavors on cheeses. Through this work he isolated and identified the fungi ''

Penicillium camemberti ''Penicillium camemberti'' is a species of fungus in the genus ''Penicillium''. It is used in the production of Camembert, Brie, Langres, Coulommiers, and Cambozola cheeses, on which colonies of ''P. camemberti'' form a hard, white crust. I ...

'' and ''

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 1914, Thom became the Chief of the Microbiological Laboratory at the USDA Bureau of Chemistry, where his job was to study problems with the handling and processing of foods, and to enforce the

Pure Food and Drug Act The Pure Food and Drug Act of 1906, also known as Dr. Wiley's Law, was the first of a series of significant consumer protection laws which was enacted by Congress in the 20th century and led to the creation of the Food and Drug Administration. ...

, a

United States federal law The law of the United States comprises many levels of codified and uncodified forms of law, of which the most important is the nation's Constitution, which prescribes the foundation of the federal government of the United States, as well as va ...

that mandated federal inspection of food products. Known for his dedication to maintaining high standards in the food industry, he relished arguing court cases "in defense of sanitary practices in the handling and processing of perishable foods". In one noted case involving the

adulteration An adulterant is caused by the act of adulteration, a practice of secretly mixing a substance with another. Typical substances that are adulterated include but are not limited to food, cosmetics, pharmaceuticals, fuel, or other chemicals, that ...

of tomato

catsup Ketchup or catsup is a table condiment with a sweet and tangy flavor. The unmodified term ("ketchup") now typically refers to tomato ketchup, although early recipes used egg whites, mushrooms, oysters, grapes, mussels, or walnuts, among oth ...

, he presented partially rotten tomatoes to the jury, and, concluding his testimony, asked them "Should the American people have to eat these in their catsup?"

Selman Waksman Selman Abraham Waksman (July 22, 1888 – August 16, 1973) was a Jewish Russian-born American inventor, Nobel Prize laureate, biochemist and microbiologist whose research into the decomposition of organisms that live in soil enabled the discov ...

, who would later be another key contributor to antibiotic development, spent some months in 1915-1916 at the USDA in

Washington, DC ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan ...

under Thom, studying soil fungi. Thom's work with the food chemist James N. Currie in 1916–17 enabled them to develop a process to mass-produce

using ''Aspergillus'', and a few years later, the first large-scale mold fermentation factory had been established in

Brooklyn, New York Brooklyn () is a borough of New York City, coextensive with Kings County, in the U.S. state of New York. Kings County is the most populous county in the State of New York, and the second-most densely populated county in the United States, be ...

. This early work ultimately led to the Department of Agriculture's establishing four Regional Research Laboratories in 1938 that were devoted to industrial mold fermentations. During his time at the USDA, Thom became a world authority on the genera ''

'' and ''

''. Thom pioneered the technique of using defined, reproducible

to grow microorganisms; most of the

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

he described are still valid today. Together with Margaret B. Church, Thom maintained collections of fungus cultures for the

American Type Culture Collection ATCC or the American Type Culture Collection is a nonprofit organization which collects, stores, and distributes standard reference microorganisms, cell lines and other materials for research and development. Established in 1925 to serve as a natio ...

, established in 1925. In 1929, a year after discovering

Alexander Fleming Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish physician and microbiologist, best known for discovering the world's first broadly effective antibiotic substance, which he named penicillin. His discovery in 1928 of w ...

published a well-known paper in which he identified the mold '' Penicillium rubrum'' as the one responsible for creating the drug. Harold Raistrick succeeded in growing the organism on a simple culture medium, but could not isolate the penicillin produced by the mold when grown this way. With Thom's assistance, they identified the organism as ''

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 ...

'' and, in 1941, developed a method to scale up production at the Department of Agriculture's Northern Regional Research Laboratory in

Peoria, Illinois Peoria ( ) is the county seat of Peoria County, Illinois, United States, and the largest city on the Illinois River. As of the United States Census, 2020, 2020 census, the city had a population of 113,150. It is the principal city of the Peoria ...

, which ultimately resulted in an inexpensive supply of the drug. Fleming's mold was correctly identified as ''

Penicillium rubens ''Penicillium rubens'' is a species of fungus in the genus ''Penicillium'' and was the first species known to produce the antibiotic penicillin. It was first described by Philibert Melchior Joseph Ehi Biourge in 1923. For the discovery of penicil ...

'' in 2011. Thom held his job with the Bureau of Chemistry until 1927, when the position was abolished. He was then appointed Principal Mycologist of the Division of Soil Microbiology for the newly created Bureau of Chemistry and Soils. In a few years, Thom became known as an authority on

soil microbiology Soil microbiology is the study of microorganisms in soil, their functions, and how they affect soil properties. It is believed that between two and four billion years ago, the first ancient bacteria and microorganisms came about on Earth's oceans. ...

, and was often invited to present papers at national and international meetings. In one of Thom's important contributions to the field, he led the research group responsible for advances that enabled the control of

cotton root rot Texas root rot (also known as Phymatotrichopsis root rot, Phymatotrichum root rot, cotton root rot, or, in the older literature, Ozonium root rot) is a pathogen, disease that is fairly common in Mexico and the southwestern United States resulting ...

, which at the time was a major problem in the southwestern United States. In collaboration with his protégé Kenneth Raper, they published the ''Manual of Penicillin'' in 1940. Thom formally retired in 1942, although he remained active as a consultant and guest speaker until shortly before his death.

Memberships and honors

Thom was the U.S. Delegate to the 1905 International Dairy Congress held in Paris, France. He helped establish a graduate education program at the USDA. In 1907, he became a charter member of the Dairy Association of America, and in 1918, was appointed President of the Bacteriological Association of Washington. He attended the 1935 International Soil Congress in Oxford, England and was Vice President of the 1939 International Microbiological Congress in New York. He was a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

, a charter member of the

Mycological Society of America The Mycological Society of America (MSA) is a learned society that serves as the professional organization of mycologists in the U.S. and Canada. It was founded in 1932. The Society's constitution states that "The purpose of the Society is to prom ...

, and president of the

Society of American Bacteriologists The American Society for Microbiology (ASM), originally the Society of American Bacteriologists, is a professional organization for scientists who study viruses, bacteria, fungi, algae, and protozoa as well as other aspects of microbiology. It wa ...

in 1940 and the Society of Industrial Microbiology in 1950. Thom was awarded an Honorary Doctor of Science degree by Lake Forest College in 1936. For his work on penicillin, he and his research group received the Lasker Group Award in 1946, and the USDA Distinguished Service Award in 1947. The same year, he received a gold medal from the

Spanish National Research Council The Spanish National Research Council ( es, Consejo Superior de Investigaciones Científicas, CSIC) is the largest public institution dedicated to research in Spain and the third largest in Europe. Its main objective is to develop and promote res ...

for his contributions to microbiology and medicine.

Described taxa

*''

Aspergillus alliaceus ''Aspergillus alliaceus'' is a species of fungus in the genus ''Aspergillus''. It is from the ''Flavi'' section. It was first described scientifically by Charles Thom and Margaret Church in 1926. Its associated teleomorph In mycology, the t ...

'' Thom & Church 1926 *'' Aspergillus caespitosus'' Raper & Thom 1944 *'' Aspergillus foetidus'' Thom & Raper 1945 *'' Aspergillus fonsecaeus'' Thom & Raper 1965 *'' Aspergillus granulosus'' Raper & Thom 1944 *'' Aspergillus janus'' Raper & Thom 1944 *'' Aspergillus niveoglaucus'' Thom & Raper 1941 *'' Aspergillus panamensis'' Raper & Thom 1944 *'' Aspergillus quadrilineatus'' Thom & Raper 1939 *'' Aspergillus ruber'' Thom & Church 1926 *'' Aspergillus rugulosus'' Thom & Raper 1939 *'' Aspergillus schiemanniae'' Thom 1916 *'' Aspergillus sparsus'' Raper & Thom 1944 *''

Aspergillus terreus ''Aspergillus terreus'', also known as ''Aspergillus terrestris'', is a fungus (mold) found worldwide in soil. Although thought to be strictly asexual until recently, ''A. terreus'' is now known to be capable of sexual reproduction. This saprotr ...

'' Thom 1918 *'' Aspergillus variecolor'' Thom & Raper 1939 *'' Eupenicillium gladioli'' L. McCulloch & Thom 1928 *'' Penicillium atramentosum'' Thom 1910 *'' Penicillium avellaneum'' Thom & Turesson 1915 *'' Penicillium biforme'' Thom 1910 *'' Penicillium brasiliense'' Thom 1930 *''

'' Thom 1906 *''

Penicillium chrysogenum ''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 ...

'' Thom 1910 *''

Penicillium citrinum ''Penicillium citrinum'' is an anamorph, mesophilic fungus species of the genus of ''Penicillium'' which produces tanzawaic acid A-D, ACC, Mevastatin, Quinocitrinine A, Quinocitrinine B, and nephrotoxic citrinin. ''Penicillium citrinum'' ...

'' Thom 1910 *'' Penicillium columnare'' Thom 1930 *'' Penicillium commune'' Thom 1910 *'' Penicillium crustosum'' Thom 1930 *''

'' Thom 1906 *'' Penicillium rugulosum'' Thom 1910

Selected publications

*Thom, Charles (1906) "Fungi in cheese ripening; Camembert and Roquefort" in USDA Bureau of Animal Industry Bulletin 82 pp. 1–39 *Thom, Charles (1910) "Cultural studies of species of ''Penicillium''" in USDA Bureau of Animal Industry Bulletin 118 pp. 1–109 *Thom, Charles; Currie, James N. (1916) "''Aspergillus niger'' group" in Journal of Agricultural Research 7:1 pp. 1–15 * * *Thom, Charles; Hunter, Albert Clayton (1924). "Hygienic Fundamentals of Food Handling" 228 pp. *Thom, Charles; Church, Margaret B. (1926). "The Aspergilli". 272 pp. *Thom, Charles (1930). "The Penicillia". 644 pp. *

References

External links

Charles Thom Papers
at th
Archives of the New York Botanical Garden
including correspondence, manuscripts, research notes, an index card file of mycological literature, photographs, negatives, drawings, and personal papers * * {{DEFAULTSORT:Thom, Charles 1872 births 1956 deaths People from Minonk, Illinois Lake Forest Academy alumni Lake Forest College alumni University of Missouri alumni American mycologists Members of the United States National Academy of Sciences

Early life

Career

Memberships and honors

Described taxa

Selected publications

See also

References

External links