Herman Jan Phaff (May 30, 1913 – August 24, 2001) was a scientist who specialised in yeast ecology. He was born in the Netherlands before moving to California 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 of yeast.

Biography

Early life and education

Phaff was born in Winschoten, Netherlands. His family owned a winery where he became interested in the microorganisms 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 wine. He studied chemical engineering at Technical University Delft, writing a dissertation on the pectinases of '' Penicillium chrysogenum''. On the advice of Albert Kluyver, when he was 26 years old he moved to California to study as a post-graduate at UC Berkeley.

Career

While at Berkeley, Phaff worked in

Emil Mrak Emil Marcel Mrak (October 27, 1901 – April 9, 1987) was an American food scientist, microbiologist, and second chancellor of the University of California, Davis. He was recognized internationally for his work in food preservation and as a world ...

'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 as ...

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

Maynard Joslyn Maynard Alexander Joslyn (July 7, 1904 – November 28, 1984) was a Russian Empire-born, American food scientist who involved in the rebirth of the American wine industry in California following the repeal of Prohibition in 1933. Joslyn was also i ...

and focussed on yeast taxonomy, ecology and physiology. After completing his PhD in 1943, he accepted a faculty position at Berkeley, before moving to the food science department of UC Davis in 1954. During the 1950s, he wrote several classic scientific papers, published in '' Nature'' on yeast pectinases with Arnold Demain. Whilst at UC Davis, he worked with the Chinese born food scientist,

Bor S. Luh Bor Shium Luh (January 13, 1916 – June 4, 2001) was a Chinese-born American food scientist who was known was for his research in fruit and vegetable products and in developing food science and technology in Asia, Latin America, and the Middle Eas ...

. In 1969 he was named University of California at Davis Faculty Research Lecturer. In 1985 he co-authored a definitive book on viticulture with

Maynard Amerine Maynard Andrew Amerine (1911–1998) was a pioneering researcher in the cultivation, fermentation, and sensory evaluation of wine. His academic work at the University of California at Davis is recognized internationally. His 16 books and some ...

. 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 intended to further the progress of science, usually by reporting new research. Content Articles in scientific journals are mostly written by active scientists such as s ...

s including the '' Yeast Newsletter'', the '' Journal of Bacteriology'', the '' Canadian Journal of Microbiology'' and the '' International Journal of Systematic Bacteriology''.

Species classification

Phaff was a pioneer of using molecular techniques to

classify Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood. Classification is the grouping of related facts into classes. It may also refer to: Business, organizat ...

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 The Cystofilobasidiaceae are a family of fungi in the order Cystofilobasidiales. Phylogenetic analyses shows that this family is clearly distinct from other yeast-like families of the Tremellomycetes. The GBIF, list 6 genus in the family; * ''Cy ...

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 (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...

pigment, astaxanthin. In 1997, Yuzo Yamada published '' Phaffomyces'', which is a genus of fungi within the Saccharomycetales 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 (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

), 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 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''.

Described taxa

*'' Cryptococcus cereanus'' (1974) from decaying '' Cereus'' cacti *'' Pichia amethionina'' (1978) from decaying Cereoid cacti and '' Drosophila'' flies feeding on them. *''

Pichia cactophila ''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...

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

Pichia heedii ''Pichia heedii'' is a species of yeast in the family Saccharomycetaceae. Described in 1978, it was found growing on a dead senita cactus plant (''Lophocereus schottii'') in the Sonoran Desert of Baja California Baja California (; 'Lower Cal ...

'' (1978) from the soft rot of the cacti '' Lophocereus schottii'' 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 G ...

of '' Scolytus tsugae'' feeding on Western Hemlock ('' Tsuga heterophylla'') *'' Bullera tsugae'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock ('' Tsuga heterophylla'') *'' Cryptococcus skinneri'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock ('' Tsuga heterophylla'') *'' Candida oregonensis'' (1962) from the

of '' Scolytus tsugae'' feeding on Western Hemlock ('' Tsuga heterophylla'') *'' Torulopsis sonorensis'' (1976) from decaying parts of cacti, most commonly the Organ Pipe Cactus ('' Stenocereus thurberi''), and from ''

Drosophila mojavensis ''Drosophila mojavensis'' is a cactophilic species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organi ...

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