Herman Jan Phaff (May 30, 1913 – August 24, 2001) was a scientist who specialised in

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

. He was born in the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

before moving to

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

at age of 26. He was active in Californian universities until his death. During his career he accumulated thousands of strains of yeast from the wild, and described 60 new

taxa In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

of yeast.

Biography

Early life and education

Phaff was born in

Winschoten Winschoten (; ) is a city with a population of 18,518 in the municipality of Oldambt (municipality), Oldambt in the northeast of the Netherlands. It is the largest city in the region of Oldambt (region), Oldambt in the province of Groningen (prov ...

, Netherlands. His family owned a

winery A winery is a building or property that produces wine, or a business involved in the cultivation and production of wine, such as a wine company. Some wine companies own many wineries. Besides wine making equipment, larger wineries may also feat ...

where he became interested in the

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s involved in

brewing Brewing is the production of beer by steeping a starch source (commonly cereal grains, the most popular of which is barley) in water and #Fermenting, fermenting the resulting sweet liquid with Yeast#Beer, yeast. It may be done in a brewery ...

beer and

fermenting Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduced ...

wine. He studied

chemical engineering Chemical engineering is an engineering field which deals with the study of the operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials ...

Technical University Delft The Delft University of Technology (TU Delft; ) is the oldest and largest Dutch public technical university, located in Delft, Netherlands. It specializes in engineering, technology, computing, design, and natural sciences. It is considered one o ...

, writing a dissertation on the

pectinase Pectinases are a group of enzymes that breaks down pectin, a polysaccharide found in plant cell walls, through hydrolysis, transelimination and deesterification reactions. Commonly referred to as pectic enzymes, they include pectolyase, pectozym ...

s of ''

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 ...

''. On the advice of

Albert Kluyver Albert Jan Kluyver ForMemRS (3 June 1888 – 14 May 1956) was a Dutch microbiologist and biochemist. Career In 1926, Kluyver and Hendrick Jean Louis Donker published the now classic paper, "Die Einheit in der Biochemie" ("Unity in Biochemis ...

, when he was 26 years old he moved to California to study as a post-graduate at

UC Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a public land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkele ...

Career

While at Berkeley, Phaff worked in Emil Mrak's laboratory, who is said to have had a major influence on him. When he first arrived, he was most interested in studying

fruit juice Juice is a drink made from the extraction or pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat or seafood, such ...

s, but Mrak asked him to work on yeasts, knowing he had worked in Kluyver's laboratory. His PhD was supervised by Maynard Joslyn and focussed on yeast

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

, ecology and

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

. After completing his PhD in 1943, he accepted a faculty position at Berkeley, before moving to the

food science Food science (or bromatology) is the basic science and applied science of food; its scope starts at overlap with agricultural science and nutritional science and leads through the scientific aspects of food safety and food processing, informing ...

department of

UC Davis The University of California, Davis (UC Davis, UCD, or Davis) is a Public university, public Land-grant university, land-grant research university in Davis, California, United States. It is the northernmost of the ten campuses of the University ...

in 1954. During the 1950s, he wrote several classic scientific papers, published in ''

Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

'' on yeast pectinases with

Arnold Demain Arnold L. Demain (April 26, 1927 – April 3, 2020) was an American microbiologist. During his 60-year career, he gained a reputation in the field of industrial microbiology. He was the Professor of Industrial Microbiology in the Biology D ...

. Whilst at UC Davis, he worked with the Chinese born food scientist, Bor S. Luh. In 1969 he was named University of California at Davis Faculty Research Lecturer. In 1985 he co-authored a definitive book on

viticulture Viticulture (, "vine-growing"), viniculture (, "wine-growing"), or winegrowing is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of ''Vitis vinifera'', the common grape vine ...

with Maynard Amerine. Despite officially retiring in 1983, he maintained a busy laboratory and continued to conduct research daily. His contributions to the study of yeast ecology are unparalleled. At various times in his career he was an editor of several

scientific journal In academic publishing, a scientific journal is a periodical publication designed to further the progress of science by disseminating new research findings to the scientific community. These journals serve as a platform for researchers, schola ...

s including the '' Yeast Newsletter'', the ''

Journal of Bacteriology A journal, from the Old French ''journal'' (meaning "daily"), may refer to: *Bullet journal, a method of personal organization *Diary, a record of personal secretive thoughts and as open book to personal therapy or used to feel connected to onesel ...

'', the ''

Canadian Journal of Microbiology The ''Canadian Journal of Microbiology'' is a monthly peer-reviewed scientific journal covering all aspects of microbiology. It was established in 1954 and is published by NRC Research Press. The editors-in-chief are Kari Dunfield (University of Gu ...

'' and the ''

International Journal of Systematic Bacteriology The ''International Journal of Systematic and Evolutionary Microbiology'' is a peer-reviewed scientific journal covering research in the field of microbial systematics that was established in 1951. Its scope covers the taxonomy, nomenclature, iden ...

''.

Species classification

Phaff was a pioneer of using

molecular techniques Molecular biology is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. Though cells and other microscop ...

classify Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

yeasts, along with his colleagues and students, Phaff described over 60 yeast taxa through his career. In 1976, the yeast genus '' Phaffia'' (in the Cystofilobasidiaceae family) was isolated from tree exudates and was named after Phaff, by Martin Miller and two Japanese colleagues, in recognition of his contributions to yeast taxonomy and ecology. The species, '' Phaffia rhodozyma'' is economically important today because it synthesises the

carotenoid Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...

pigment,

astaxanthin Astaxanthin is a keto- carotenoid within a group of chemical compounds known as carotenoids or terpenes. Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-solu ...

. In 1997, Yuzo Yamada published '' Phaffomyces'', which is a genus of fungi within the

Saccharomycetales Saccharomycetales belongs to the kingdom of Fungi and the division Ascomycota. It is the only order in the class Saccharomycetes. There are currently 13 families recognized as belonging to Saccharomycetales. GBIF also includes; Alloascoideaceae ...

order, also named in his honour..

Yeast collection

Through his 60-year career he collected 6400 yeast strains from animals, soil and plants (including over 1000 from

cacti A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

), from countries all around the world. There are few collections of microbial cultures so large that have been accumulated by institutions and likely none so large that have been accumulated by any other single researcher. The collection, known as the Phaff Yeast Culture Collection contains 400 of the 700 identified species of yeast and has been described as priceless, with a large number of

wild type The wild type (WT) is the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, " ...

isolates making it unique amongst yeast collections. According to the current curator, 80% of the yeasts in the collection are not available from other sources. A 2003 yeast symposium organized by

FEMS Federation of European Microbiological Societies (FEMS) is an international European scientific organization, formed by the union of a number of national organizations; there are now 57 members from 41 European countries, regular and provisional. ...

(Federation of European Microbiological Societies) was named in his memory and the talks were summarised in a special edition of ''

International Microbiology ''International Microbiology'' is a quarterly peer-reviewed scientific journal published by Springer Science+Business Media and the official journal of the . It covers all aspects of microbiology. The journal was established in 1947 as ''Microbiolo ...

''.

Described taxa

*'' Cryptococcus cereanus'' (1974) from decaying '' Cereus'' cacti *'' Pichia amethionina'' (1978) from decaying Cereoid cacti and ''

Drosophila ''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ...

'' flies feeding on them. *'' Pichia cactophila'' (1978) from decaying cacti and ''

'' flies feeding on them. *'' Pichia heedii'' (1978) from the soft rot of the cacti ''

Lophocereus schottii ''Lophocereus schottii'', the senita cactus, is a species of cactus from southern Arizona and north-western Mexico, particularly Baja California and Sonora. Description ''Lophocereus schottii'' grows tree-shaped to shrub-like with yellow-green, ...

'' and '' Drosophila pachea''. *'' Sporobolomyces singulari'' (1962) from the

frass Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...

of '' Scolytus tsugae'' feeding on Western Hemlock (''

Tsuga heterophylla ''Tsuga heterophylla'', the western hemlock or western hemlock-spruce, is a species of Tsuga, hemlock native to the northwest coast of North America, with its northwestern limit on the Kenai Peninsula, Alaska, and its southeastern limit in nort ...

'') *'' Bullera tsugae'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock (''

'') *'' Cryptococcus skinneri'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock (''

'') *'' Candida oregonensis'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock (''

'') *'' Torulopsis sonorensis'' (1976) from decaying parts of cacti, most commonly the Organ Pipe Cactus (''

Stenocereus thurberi ''Stenocereus thurberi'', the organ pipe cactus, is a species of cactus native to Mexico and the United States. The species is found in rocky desert. Two subspecies are recognized based on their distribution and height. The Organ Pipe Cactus Nati ...

''), and from ''

Drosophila mojavensis ''Drosophila mojavensis'' is a cactophilic species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual repr ...

''. *'' Pichia opuntiae'' (1979) from the

cladode Phylloclades and cladodes are flattened, photosynthesis, photosynthetic shoots, which are usually considered to be modified branches. The two terms are used either differently or interchangeably by different authors. ''Phyllocladus'', a genus of ...

s of '' Opuntia inermis'' in Australia and from the decaying parts of Cereoid cacti in North America.

References

External links

Phaff Yeast Culture Collection Web Site
{{DEFAULTSORT:Phaff, Herman 1913 births 2001 deaths Dutch emigrants to the United States American microbiologists Delft University of Technology alumni University of California, Davis faculty