Herman Phaff
Encyclopedia
Herman Jan Phaff 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 strain
s of yeast from the wild, and described 60 new taxa
of yeast.
, The Netherlands. His family owned a winery
where he became interested in the microorganism
s involved in brewing
beer and fermenting
wine. He studied chemical engineering
at Technical University Delft, writing a dissertation on the pectinase
s 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.
, 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
. 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. His contributions to the study of yeast ecology are unparalleled. At various times in his career he was an editor of several scientific journal
s including the Yeast Newsletter, the Journal of Bacteriology, the Canadian Journal of Microbiology and the International Journal of Systematic Bacteriology.
to classify yeasts, along with his colleagues and students, Phaff described over 60 yeast taxa through his career. In 1976, the yeast genus Phaffia 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
pigment, astaxanthin
.
s 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. 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) was named in his memory and the talks were summarised in a special edition of International Microbiology
.
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
. He was born in The Netherlands before moving to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
at age of 26. He was active in Californian universities until his death. During his career he accumulated thousands of strain
Strain (biology)
In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
s of yeast from the wild, and described 60 new taxa
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
of yeast.
Early life and education
Phaff was born in WinschotenWinschoten
Winschoten is a former municipality and city in the northeast of the Netherlands.Population : 18.497; area: 22,24 km2.The origin of the name of Winschoten is not known but it has received nicknames. One of these is Molenstad . It has also been known, in living memory, as Sodom...
, The Netherlands. His family owned a winery
Winery
A winery is a building or property that produces wine, or a business involved in the production of wine, such as a wine company. Some wine companies own many wineries. Besides wine making equipment, larger wineries may also feature warehouses, bottling lines, laboratories, and large expanses of...
where he became interested in the microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s involved in brewing
Brewing
Brewing is the production of beer through steeping a starch source in water and then fermenting with yeast. Brewing has taken place since around the 6th millennium BCE, and archeological evidence suggests that this technique was used in ancient Egypt...
beer and fermenting
Fermentation (wine)
The process of fermentation in wine turns grape juice into an alcoholic beverage. During fermentation, yeast interact with sugars in the juice to create ethanol, commonly known as ethyl alcohol, and carbon dioxide...
wine. He studied chemical engineering
Chemical engineering
Chemical engineering is the branch of engineering that deals with physical science , and life sciences with mathematics and economics, to the process of converting raw materials or chemicals into more useful or valuable forms...
at Technical University Delft, writing a dissertation on the pectinase
Pectinase
Pectinase is a general term for enzymes, such as pectolyase, pectozyme and polygalacturonase, commonly referred to in brewing as pectic enzymes. These break down pectin, a polysaccharide substrate that is found in the cell walls of plants. One of the most studied and widely used commercial...
s of Penicillium chrysogenum
Penicillium chrysogenum
Penicillium chrysogenum is common in temperate and subtropical regions and can be found on salted food products, but it is mostly found in indoor environments, especially in damp or waterdamaged buildings. It was previously known as Penicillium notatum. It has rarely been reported as a cause of...
. On the advice of Albert Kluyver
Albert Kluyver
Albert Jan Kluyver was a Dutch microbiologist and biochemist.In 1926 Kluyver and Hendrick Jean Louis Donker published the now classic paper, "Die Einheit in der Biochemie" , a paper helped establish Kluyver's vision that, at a biochemical level, all organisms are unified...
, 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's laboratory, who is said to have had a major influence on him. 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. His PhD was supervised by Maynard Joslyn and focussed on yeast taxonomyTaxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
, ecology and physiology
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
. After completing his PhD in 1943, he accepted a faculty position at Berkeley, before moving to the food science
Food science
Food science is a study concerned with all technical aspects of foods, beginning with harvesting or slaughtering, and ending with its cooking and consumption, an ideology commonly referred to as "from field to fork"...
department of UC Davis in 1954. During the 1950s, he wrote several classic scientific papers, published in Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
on yeast pectinases with Arnold Demain
Arnold Demain
Arnold Demain is an American microbiologist. During his 60 year long career, he has gained a renowned reputation in the field of industrial microbiology. The August 2010 edition of The Journal of Antibiotics celebrated his scientific career....
. Whilst at UC Davis, he worked with the Chinese born food scientist, Bor S. Luh
Bor S. Luh
Bor Shium Luh 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 East....
. In 1969 he was named University of California at Davis Faculty Research Lecturer. In 1985 he co-authored a definitive book on viticulture
Viticulture
Viticulture is the science, production and study of grapes which deals with the series of events that occur in the vineyard. When the grapes are used for winemaking, it is also known as viniculture...
with Maynard Amerine
Maynard Amerine
Maynard Amerine 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...
. 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
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...
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 techniquesMolecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
to classify yeasts, along with his colleagues and students, Phaff described over 60 yeast taxa through his career. In 1976, the yeast genus Phaffia 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
Carotenoid
Carotenoids are tetraterpenoid organic pigments that are naturally occurring in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms like algae, some bacteria, and some types of fungus. Carotenoids can be synthesized fats and other basic organic metabolic building...
pigment, astaxanthin
Astaxanthin
Astaxanthin is a carotenoid. It belongs to a larger class of phytochemicals known as terpenes. It is classified as a xanthophyll, which means "yellow leaves". Like many carotenoids, it is a colorful, lipid-soluble pigment. Astaxanthin is found in microalgae, yeast, salmon, trout, krill, shrimp,...
.
Yeast collection
Through his 60-year career he collected 6400 yeast strainStrain (biology)
In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
s from animals, soil and plants (including over 1000 from cacti
Cacti
-See also:* RRDtool The underlying software upon which Cacti is built* MRTG The original Multi Router Traffic Grapher from which RRDtool was "extracted".* Munin -External links:******...
), 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
Wild type
Wild type refers to 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, "mutant" allele...
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
FEMS
FEMS, the Federation of European Microbiological Societies is an international European scientific organization, formed by the union of a number of national organizations; there are now 50 members, 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
International Microbiology is a peer-reviewed academic journal published by the Spanish Society for Microbiology; it publishes articles on all aspects of microbiology...
.
Described taxa
- Cryptococcus cereanus (1974) from decaying CereusCereusCereus is a genus of cactus. The term cereus is also used to describe cacti with very elongated bodies, including columnar growth cacti and epiphytic cacti...
cacti - Pichia amethionina (1978) from decaying Cereoid cacti and DrosophilaDrosophilaDrosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
flies feeding on them. - Pichia cactophila (1978) from decaying cacti and DrosophilaDrosophilaDrosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
flies feeding on them. - Pichia heediiPichia heediiPichia heedii is a species of yeast in the family Saccharomycetaceae. Described in 1978, it was found growing on a dead senita cactus plant in the Sonoran Desert of Baja California, Mexico. The species was named to honor William B. Heed and his contributions to the study of desert-adapted yeasts....
(1978) from the soft rot of the cacti Lophocereus schottii and Drosophila pachea. - Sporobolomyces singulari (1962) from the frassFrassFrass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...
of Scolytus tsugae feeding on Western Hemlock (Tsuga heterophylla) - Bullera tsugae (1962) from the frassFrassFrass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...
of Scolytus tsugae feeding on Western Hemlock (Tsuga heterophylla) - Cryptococcus skinneri (1962) from the frassFrassFrass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...
of Scolytus tsugae feeding on Western Hemlock (Tsuga heterophylla) - Candida oregonensis (1962) from the frassFrassFrass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...
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.
- Pichia opuntiae (1979) from the cladodes of Opuntia inermis in Australia and from the decaying parts of Cereoid cacti in North America.