Herman Jan Phaff (May 30, 1913 – August 24, 2001)[1] was a scientist who specialised in
yeastecology. 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.
While at Berkeley, Phaff worked in
Emil Mrak's laboratory, who is said to have had a major influence on him.[2][3] When he first arrived, he was most interested in studying
fruit juices, but Mrak asked him to work on yeasts, knowing he had worked in Kluyver's laboratory.[4] His PhD was supervised by
Maynard Joslyn 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.[2][3][5] Whilst at UC Davis, he worked with the Chinese born food scientist,
Bor S. Luh.[6] 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. Despite officially retiring in 1983, he maintained a busy laboratory and continued to conduct research daily.[3] His contributions to the study of yeast ecology are unparalleled.[7] At various times in his career he was an editor of several
scientific journals including the Yeast Newsletter, the Journal of Bacteriology, the Canadian Journal of Microbiology and the International Journal of Systematic Bacteriology.[2]
Species classification
Phaff was a pioneer of using
molecular techniques to
classify yeasts, along with his colleagues and students, Phaff described over 60 yeast taxa through his career.[2] 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.[8] The species, Phaffia rhodozyma is economically important today because it synthesises the
carotenoid pigment,
astaxanthin.[7]
Through his 60-year career he collected 6400 yeast
strains from animals, soil and plants (including over 1000 from
cacti), 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.[3][11] According to the current curator, 80% of the yeasts in the collection are not available from other sources.[12] A 2003 yeast symposium organized by
FEMS (Federation of European Microbiological Societies) was named in his memory[13] and the talks were summarised in a special edition of International Microbiology.[14]
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abcdPhaff, H. J.; Carmo-Sousa, L. (1962). "Four new species of yeast isolated from insect frass in bark of Tsuga heterophylla (Raf.) Sargent". Antonie van Leeuwenhoek. 28: 193–207.
doi:
10.1007/BF02538734.
PMID13943102.
S2CID26462843.