Otto Kandler (23 October 1920 in
Deggendorf
Deggendorf () is a town in Bavaria, Germany, capital of the Deggendorf district.
It is located on the left bank approximately in the middle between the Danube cities of Regensburg and Passau. The Danube forms the town's natural border towards ...
– 29 August 2017 in
Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the States of Germany, German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the List of cities in Germany by popu ...
,
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...
)
was a
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...
and
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 ...
. Until his retirement in 1986 he was professor of botany at the
Ludwig Maximilian University of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...
.
![1983-12 Otto Kandler mit Pseudomurein-Modell - Archiv Fam](https://upload.wikimedia.org/wikipedia/commons/d/db/1983-12_Otto_Kandler_mit_Pseudomurein-Modell_-_Archiv_Fam._Kandler.jpg)
His most important research topics were
photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
, plant
carbohydrate metabolism
Carbohydrate metabolism is the whole of the biochemistry, biochemical processes responsible for the metabolic anabolism, formation, catabolism, breakdown, and interconversion of carbohydrates in life, living organisms.
Carbohydrates are central t ...
, analysis of the structure of bacterial
cell wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mech ...
s (
murein
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ba ...
/
peptidoglycan
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ...
), the systematics of ''
Lactobacillus
''Lactobacillus'' is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metabolically diver ...
'', and the
chemotaxonomy
Webster's Dictionary, Merriam-Webster defines ''chemotaxonomy'' as the method of biology, biological classification based on similarities and dissimilarity in the structure of certain chemical compound, compounds among the organisms being classifi ...
of plants and microorganisms.
He presented the first experimental evidence for the existence of
photophosphorylation In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions, driven by the main primary source of ...
''in vivo''.
His discovery of the basic differences between the cell walls of
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
and
archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
(up to 1990 called "archaebacteria") convinced him that archaea represent an autonomous group of organisms distinct from bacteria.
This was the basis for his cooperation with
Carl Woese
Carl Richard Woese (; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, ...
and made him the founder of research on the ''Archaea'' in Germany. In 1990, together with Woese, he proposed the three
domains of life:
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
,
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
,
Eucarya.
Life and education
Otto Kandler was born on 23 October 1920 in
Deggendorf
Deggendorf () is a town in Bavaria, Germany, capital of the Deggendorf district.
It is located on the left bank approximately in the middle between the Danube cities of Regensburg and Passau. The Danube forms the town's natural border towards ...
,
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...
, as the 6th child of the family of a market gardener. Growing up and helping in his father's garden, early on, he became interested in plant life and nature in general.
He attended school for 8 years. When he was about twelve years old he had read about
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended fr ...
and mentioned it to a Catholic priest. The priest punished him with two strikes on his hands with a rod. However he remained interested in the origin and evolution of organisms for the rest of his life.
His parents could not afford to pay the fees for the
gymnasium, and he was supposed to become a gardener or learn another trade. However his teachers convinced his parents that their talented son should continue school. So he attended the "Deutsche Aufbauschule" in
Straubing
Straubing () is an independent city in Lower Bavaria, southern Germany. It is seat of the district of Straubing-Bogen. Annually in August the Gäubodenvolksfest, the second largest fair in Bavaria, is held.
The city is located on the Danube form ...
, Bavaria, a school for the education of future teachers. His studies were, however, interrupted by the Second World War. In 1939 he and his fellow students had to join the
Reichsarbeitsdienst
The Reich Labour Service (''Reichsarbeitsdienst''; RAD) was a major organisation established in Nazi Germany as an agency to help mitigate the effects of unemployment on the German economy, militarise the workforce and indoctrinate it with Nazi ...
, later he had to serve in the German army as a radio reporter in Russia. At the end of the war his group was transferred to Austria. He escaped by bicycle to the Western Front to avoid capture by the Russians. After spending a few months in an American prison camp he was allowed to return home. Between 1945 and 1946 he reconstructed his father's market garden and earned some money by growing and selling vegetable, especially cabbage, and flowers to finance his life and his future studies.
Kandler was very interested in science, but only in 1946 was he able to enrol at
Ludwig Maximilian University of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...
in
botany
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
, zoology, geology, chemistry and physics. He also attended philosophy lectures. Since much of the university of Munich had been bombed, the institute buildings were badly damaged and still in ruins. To be admitted, he and all the other students had to remove rubble and help reconstruct buildings.
After three terms he found a research subject for his dissertation in botany. As the first in Germany he started to cultivate isolated plant tissues ''in vitro''. He used these tissue cultures to study for instance
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
and the influence of
auxin
Auxins (plural of auxin ) are a class of plant hormones (or plant-growth regulators) with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essenti ...
s under defined ''in vitro'' conditions, received his doctor's degree with honors in 1949 and became assistant professor of botany at the University of Munich. After his
habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a ...
in 1953 he remained at the university until 1957.
In 1953 he married Gertraud Schäfer, a graduate student of microbiology. They have three daughters and four grandchildren.
For his early publications on
photophosphorylation In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions, driven by the main primary source of ...
he received a generous research fellowship from the
Rockefeller Foundation
The Rockefeller Foundation is an American private foundation and philanthropic medical research and arts funding organization based at 420 Fifth Avenue, New York City. The second-oldest major philanthropic institution in America, after the Carneg ...
and, in 1956/1957 he was able to work on basic questions of photosynthesis for one year in the USA.
After his return, Kandler was dissatisfied with the poor laboratory conditions at the university at home, so he was glad to find a position as director of the Bacteriological Institute of the South German Dairy Research Center in Freising-
Weihenstephan
Weihenstephan is a part of Freising north of Munich, Germany. It is located on the Weihenstephan Hill, named after the Weihenstephan Abbey, in the west of the city.
Weihenstephan is known for:
* the Benedictine Weihenstephan Abbey, founded 725, ...
in 1957, where conditions were much better.
In 1960 he was appointed full professor of Applied Botany of the
Technical University Munich
The Technical University of Munich (TUM or TU Munich; german: Technische Universität München) is a public research university in Munich, Germany. It specializes in engineering, technology, medicine, and applied and natural sciences.
Establis ...
, where research conditions still at that time were bad. So he kept his position in Weihenstephan in parallel until 1965. In 1968 he was appointed full professor and Head of the Department of Botany at the
Ludwig Maximilian University of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...
, taught and conducted research until his retirement in 1986.
His broad scientific interests are indicated by the titles of his more than 400 publications.
Kandler would have celebrated his 100th birthday on 23 October 2020. For this centenary Kandler's family gave his chronological collection of historical botany books, among them
herbal
A herbal is a book containing the names and descriptions of plants, usually with information on their medicinal, tonic, culinary, toxic, hallucinatory, aromatic, or magical powers, and the legends associated with them.Arber, p. 14. A herbal m ...
s of the 16th and 17th centuries, as a present to the library of the “Regensburgische Botanische Gesellschaft” (founded by
David Heinrich Hoppe
David Heinrich Hoppe (15 December 1760 – 1 August 1846) was a German pharmacist, botanist, entomologist and physician. He is remembered for contributions made to the study of alpine flora.
Life
Hoppe, a merchant's son from Vilsen, Hanover, ...
), which has been included in the library of the
University of Regensburg
The University of Regensburg (german: link=no, Universität Regensburg) is a public research university located in the medieval city of Regensburg, Bavaria, a city that is listed as a UNESCO World Heritage Site. The university was founded on 18 ...
. Through digitization these historical sources soon will be generally accessible.
Plant physiology
Otto Kandler was very interested in plant growth processes,
photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
,
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
, especially of
carbohydrates
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...
.
As the first in Germany he started to grow isolated plant tissue cultures (e.g. of stems, roots, sprouts, embryos, callus growths) ''in vitro''
to study metabolism and the effect of
auxin
Auxins (plural of auxin ) are a class of plant hormones (or plant-growth regulators) with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essenti ...
s under defined ''in vitro'' conditions. As mentioned above, this formed the subject of his dissertation (summa cum laude) in 1949.
In his contribution „Historical perspectives on queries concerning photophosphorylation" Kandler describes the beginnings of
photophosphorylation In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions, driven by the main primary source of ...
research and how he became interested: In 1948, he was inspired by a lecture on the phosphate metabolism of yeast by
Feodor Lynen
Feodor Felix Konrad Lynen (; 6 April 19116 August 1979) was a German biochemist. In 1964 he won the Nobel Prize in Physiology or Medicine together with Konrad Bloch for their discoveries concerning the mechanism and regulation of cholesterol an ...
(1964
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
). In these years, in the aftermath of World War II, the original Chemical Institute of the
Ludwig Maximilian University of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...
was still in ruins and Feodor Lynen and his assistant Helmut Holzer were working temporarily as guests in the Botanical Institute just next door to the laboratory where Kandler was engaged in his thesis in botany. Kandler was impressed by the experimental methods in Lynen's laboratory and got acquainted with them; Holzer and Kandler became close friends.
At that time, Holzer was able to present the first evidence for ATP formation in yeast oxidizing butanol to butyric acid. Kandler then decided to transfer their techniques to measuring phosphorylation rates ''in vivo'' to photosynthesis studies in ''Chlorella''.
So, in 1950, he was the first to present experimental evidence for the light-dependent formation of
ATP (
photophosphorylation In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions, driven by the main primary source of ...
) ''in vivo'' in intact ''
Chlorella
''Chlorella'' is a genus of about thirteen species of single-celled green algae belonging to the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the ...
'' cells.
In 1954,
Daniel I. Arnon discovered photophosphorylation ''in vitro'' using isolated
chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...
s and mentioned Kandler's pioneering work.
Kandler's early publications on light-dependent formation of ATP
led the
Rockefeller Foundation
The Rockefeller Foundation is an American private foundation and philanthropic medical research and arts funding organization based at 420 Fifth Avenue, New York City. The second-oldest major philanthropic institution in America, after the Carneg ...
to offer him a one-year research fellowship in the USA. So in 1956–1957 he worked for 6 months with Martin Gibbs at the
Brookhaven National Laboratory
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base and Japanese internment c ...
and then for another 6 months with
Melvin Calvin
Melvin Ellis Calvin (April 8, 1912 – January 8, 1997) was an American biochemist known for discovering the Calvin cycle along with Andrew Benson and James Bassham, for which he was awarded the 1961 Nobel Prize in Chemistry. He spent most of hi ...
(1961
Nobel Prize in Chemistry
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "M ...
) at the
University of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...
on central questions of photosynthesis (e.g. the path of carbon in photosynthesis, today called the
Calvin-Benson-Bassham Cycle).
The method of
radioactive labelling, i.e. the use of
radioactive isotopes
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
for tracing the path of e.g. carbon in photosynthesis, was brought to Germany by Kandler.
Together with his coworkers, Kandler demonstrated the occurrence of
ADP-glucose, the glucose donor of starch biosynthesis, for the first time in plants. He made an essential contribution to clarify the complicated biosynthesis of branched-chain monosaccharides (hamamelose,
apiose
Apiose is a branched-chain sugar found as residues in galacturonans-type pectins; that occurs in parsley and many other plants. Apiose is a component of cell wall polysaccharides.
Apiose 1-reductase uses D-apiitol and NAD+ to produce api ...
). Finally he elucidated the biosynthesis of the sugars of the raffinose family, the most frequent
oligosaccharides
An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple sugar ...
in plants.
As a result of these findings, the function of galactinol, a galactoside of
inositol
Inositol, or more precisely ''myo''-inositol, is a carbocyclic sugar that is abundant in the brain and other mammalian tissues; it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and ...
, as a galactosyl donor, was elucidated, and hence the role of inositol as a co-factor of sugar transfer reactions in plants.
Microbiology
In addition to his interest in plant physiology and biochemistry Otto Kandler early on focused on bacteria, above all, on the presence or absence of their
cell walls, since, in the early 1950s, such wall-less microorganisms were often regarded as representatives of "urbacteria".
Together with his wife, he investigated the so-called PPLOs, (now
mycoplasms), wall-less penicillin-resistant bacteria, and
L-form bacteria
L-form bacteria, also known as L-phase bacteria, L-phase variants or cell wall-deficient (CWD) bacteria, are growth forms derived from different bacteria. They lack cell walls. Peptidoglycan (murein) is absent. Two types of L-forms are distinguish ...
(bacteria that lost their cell walls). They found that these organisms do not proliferate by binary fission but by a budding process.
These publications are still cited at present.
During his time as director of the Bacteriological Institute of the South German Dairy Research Center in Freising-
Weihenstephan
Weihenstephan is a part of Freising north of Munich, Germany. It is located on the Weihenstephan Hill, named after the Weihenstephan Abbey, in the west of the city.
Weihenstephan is known for:
* the Benedictine Weihenstephan Abbey, founded 725, ...
, Kandler concentrated on dairy microbiology and investigated the physiology, biochemistry and systematics of
''lactobacilli'', on which he wrote a chapter in Bergey's Manual, the ‘bible' of microbiologists.
In addition he published numerous papers on the isolation, description and taxonomy of other bacteria.
Kandler was one of the first scientists who, together with his group, studied the chemistry and structure of the cell walls of bacteria.
The primary structure of
peptidoglycan
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ...
(murein), the unique cell wall component of bacteria, was investigated. Kandler recognized that the amino acid sequence of peptidoglycan is a valuable
chemotaxonomic marker. The different peptidoglycan types and their taxonomic implications were described in detail by Schleifer and Kandler.
As a result, they suggested comparative cell wall chemistry as a marker for the deep branches in the phylogenetic tree of bacteria.
Kandler’s cell wall studies also included methanogenic "bacteria" (
methanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are com ...
s) and halophilic "bacteria" (
halophiles
The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, ...
).
In October 1976 Kandler discovered that two strains of the methanogen ''
Methanosarcina barkeri
'' Methanosarcina barkeri'' is the most fundamental species of the genus '' Methanosarcina'', and their properties apply generally to the genus ''Methanosarcina''. ''Methanosarcina barkeri'' can produce methane anaerobically through different m ...
'' did
not contain peptidoglycan.
Consequently, he came to the conclusion that methanogens are basically different from bacteria.
In his group, also "
halobacteria
Haloarchaea (halophilic archaea, halophilic archaebacteria, halobacteria) are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea rather than bacteria and are one of th ...
" were found to lack peptidoglycan, confirming the idea, that also these organisms are not bacteria and belong to a group of organisms soon called "archaebacteria" (in 1990 classified as ''
archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
''
).
In some "archaebacteria" Kandler and König identified
pseudomurein
Pseudopeptidoglycan (also known as pseudomurein;White, David. (1995) ''The Physiology and Biochemistry of Prokaryotes'', pages 6, 12-21. (Oxford: Oxford University Press). . PPG hereafter) is a major cell wall component of some Archaea that differs ...
, now also called
pseudopeptidoglycan
Pseudopeptidoglycan (also known as pseudomurein;White, David. (1995) ''The Physiology and Biochemistry of Prokaryotes'', pages 6, 12-21. (Oxford: Oxford University Press). . PPG hereafter) is a major cell wall component of some Archaea that differs ...
, a novel cell wall component, and elucidated its structure and biosynthesis.
The
methanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are com ...
''
Methanopyrus kandleri
In taxonomy, ''Methanopyrus'' is a genus of the Methanopyraceae.
''Methanopyrus'' is a genus of methanogen, with a single described species, ''M. kandleri''. It is a rod-shaped hyperthermophile, discovered on the wall of a black smoker from the ...
''
was named in honor of Kandler by
Karl O. Stetter as a present for Kandler's 70th birthday.
Together with Hans Günter Schlegel, Kandler was substantially involved in the foundation of the German collection of microorganisms and cell cultures
(DSMZ) in Braunschweig.
Kandler was the founder and editor of
Systematic and Applied Microbiology, co-editor of the
Archives of Microbiology and of
Zeitschrift für Pflanzenphysiologie.
Archaea and the three domains of life
Otto Kandler's main subject in microbiology was his research on ''
archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
'' (before 1990 called "archaebacteria").
His discovery (October 1976) that
peptidoglycan
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ...
(murein), a typical cell wall component of bacteria, is missing in two strains of methanogenic "bacteria" (
methanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are com ...
s)
became one of the first three pieces of evidence
that methanogens belong to a group of organisms distinct from bacteria.
Therefore, Kandler was delighted when he learned from a letter by Ralph F. Wolfe, expert on methanogens, on 11 November 1976, that Wolfe's colleague
Carl Woese
Carl Richard Woese (; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, ...
(University of Illinois, Urbana, USA) had just discovered basic differences between methanogens and bacteria with his novel
16S ribosomal RNA
16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.
The genes coding for it are referred to as 16S rRNA ...
gene sequencing method.
When Kandler received this letter, based on his new findings, he had already planned to investigate the cell walls of other methanogens together with
Marvin P. Bryant, also an expert on methanogens from the University of Illinois. Coincidentally, Bryant was just sitting in Kandler's office when Wolfe's letter arrived.
In his letter Wolfe also offered to send cultures for cell wall studies since he knew Kandler was a cell wall expert. Kandler wrote back immediately how impressed he was with Woese's findings and ideas and that he looked forward to investigate Wolfe's methanogens. In his reply Kandler also mentioned that methanogens and halophiles may be "ancient relics" that have branched off from the bulk of the prokaryotes before peptidoglycan had been "invented". He asked Wolfe to send him lyophilized cells of methanogens to analyse their cell walls.
In January 1977, Kandler visited Woese for the first time. He was immediately convinced of Woese's new concept, for his cell wall analyses matched perfectly with Woese's 16S rRNA sequencing results.
This was the beginning of a close and productive transatlantic complementary relationship and cooperation by the exchange of cultures, results and ideas. Kandler's group studied the cell wall composition and Woese's group the
16S rRNA 16S rRNA may refer to:
* 16S ribosomal RNA
16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.
The g ...
gene sequences.
In their fundamental frequently cited publication, Woese and Fox (November 1977)
introduced the term "archaebacteria", at that time, comprising only methanogens. They cited Kandler
and named the very first three pieces of evidence for the concept of the "archaebacteria":
#lack of peptidoglycan in methanogens (Kandler)
#two unusual coenzymes in methanogens (Wolfe)
#unique
rRNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosoma ...
sequences in methanogens (
Woese
Carl Richard Woese (; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, a ...
).
In this article they also used a preliminary terminology ("domains" for prokaryotes/eukaryotes; "primary kingdoms" or "urkingdoms" for the three groupings "eubacteria", "archaebacteria", and "urkaryotes"
– since 1990 bacteria, archaea and eucarya,
later corrected to eukarya).
While Woese's proposal to subdivide organisms into "three lines of descent"
at that time received little support – and even harsh criticism
– in the US, Kandler called Woese "the Darwin of the 20th century"
and was convinced that research on "archaebacteria" had a great future.
With great enthusiasm Kandler founded research on "archaebacteria" in Germany
and organised funding for this novel field.
In the spring of 1978, in Munich, Kandler organised the very first meeting on "archaebacteria". Carl Woese was invited, but was not able to participate.
In the summer of 1979, Kandler invited Woese again to give a lecture at a meeting of the "Deutsche Gesellschaft für Mikrobiologie und Hygiene" in Munich. This time Woese participated. He came to Munich for the first time and was welcomed with fanfare, a brass band concert and a dinner party in the great entrance hall of the Botanical Institute of the
Ludwig Maximilian University of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...
(photo see "Life and education").
The first international conference ever on "archaebacteria" was also organised by Kandler, again in Munich, in 1981. Both, Carl Woese and Ralph Wolfe took part. The resulting conference volume was the very first book on "archaebacteria".
At this conference convincing evidence for essential structural, biochemical and molecular differences between bacteria and "archaebacteria" was presented leading to the gradual acceptance of the concept of the "archaebacteria" as an autonomous group of organisms.
After the conference, the "archaebacteria" were celebrated by Woese, Wolfe and Kandler on an excursion to the close Alps climbing the top of Hochiss (2299 m) in the Rofan mountains (see Photos).
![PhylogeneticTree, Woese 1990](https://upload.wikimedia.org/wikipedia/commons/0/0b/PhylogeneticTree%2C_Woese_1990.PNG)
In 1985, Kandler and Zillig organised a second international conference on "archaebacteria", again in Munich.
Meanwhile, the support for the "archaebacteria" concept – and also for the idea of a phylogenetic division into three groups on the basis of 16S rRNA sequencing and additional characteristics – had grown, but had still not yet been generally accepted by the scientific community.
Also an intensive controversial discussion about the level of classification and terminology was taking place (e.g. terms like urkingdom, primary kingdom, empire etc. were considered). This discussion is documented in detail in
Sapp (2009, especially chapters 19, 20).
Finally, after about 13 years of cooperation, in their publication of 1990 (Woese, Kandler, Wheelis),
Woese and Kandler proposed a "tree of life" consisting of three lines of descent for which they introduced the term
domain
Domain may refer to:
Mathematics
*Domain of a function, the set of input values for which the (total) function is defined
**Domain of definition of a partial function
**Natural domain of a partial function
**Domain of holomorphy of a function
* Do ...
as the highest rank of classification, above the
kingdom
Kingdom commonly refers to:
* A monarchy ruled by a king or queen
* Kingdom (biology), a category in biological taxonomy
Kingdom may also refer to:
Arts and media Television
* ''Kingdom'' (British TV series), a 2007 British television drama s ...
level. They also suggested the terms ''
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
'', ''
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
'' and
''Eucarya'' (later corrected to ''Eukarya'') for the three domains and presented the formal description of the taxon ''Archaea''. Up to date, this publication is one of the most frequently cited papers in the Proceedings of the National Academy of Sciences of the United States of America.
(The role of the third author is described by Sapp (pp. 261f. and 386)
and Quammen (pp. 210f.))
![Kandler 1998 Early diversification of life and pre-cell theory](https://upload.wikimedia.org/wikipedia/commons/5/55/Kandler_1998_Early_diversification_of_life_and_pre-cell_theory.svg)
In a second publication,
they contrasted their natural system of "global classification", a
phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
division on the basis of 16S rRNA sequencing, with the conventional division of organisms into two (
procaryotes-
eucaryotes system) or into five (5-kingdom system) groupings.
Today the division of the tree of life into three domains – levels above kingdoms – is textbook knowledge.
In addition, Kandler studied the early diversification of life.
He assumed that the early evolution of organisms did not start from a common first ancestral cell, but that each domain evolved by "multiple cellularization of a multiphenotypical population of pre-cells",
where the invention of cell envelopes played an important role.
Kandler's contribution to our understanding of the early evolution of life was valued several times, e.g.
Müller 1998,
Wiegel 1998,
Wächtershäuser 2003
and 2006,
Schleifer 2011.
Applied Microbiology
Louis Pasteur
Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...
was one of Kandler's scientific heroes. Kandler liked to cite Pasteur's opinion that there is no "applied science", but that there are rather "applications of science".
When he was director of the Bacteriological Institute of the South German Dairy Research Center in Freising-
Weihenstephan
Weihenstephan is a part of Freising north of Munich, Germany. It is located on the Weihenstephan Hill, named after the Weihenstephan Abbey, in the west of the city.
Weihenstephan is known for:
* the Benedictine Weihenstephan Abbey, founded 725, ...
, he concentrated on the microbiology of milk and dairy products, e.g. developed methods to prolong the shelf-life of milk, and tested the utilisation of ''Lactobacillus acidophilus'' in starter cultures for yoghurt. He also tested several procedures for the fermentation of milk and vegetable products or proposed methods for successfully combat micro-organisms in cooling water systems (more examples see Schleifer 2011.
Later he conducted research on thermophilic
methanogen
Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are com ...
s and their ability to produce biogas from sewage or other waste.
Ecology
Kandler's role as an early representative of scientific ecology is less known. He was a cofounder of the "commission for ecology" at the
Bavarian Academy of Sciences
The Bavarian Academy of Sciences and Humanities (german: Bayerische Akademie der Wissenschaften) is an independent public institution, located in Munich. It appoints scholars whose research has contributed considerably to the increase of knowledg ...
(now "Forum für Ökologie" – panel for ecology),
of which he was a member until 2006.
His interest in ecology was broad; for instance he dealt with bacterial interactions, forest conditions and the return of lichens into the city of Munich.
Since the early 1980s, research on the so-called "Waldsterben" (forest death) in Germany was substantially sponsored by the German Ministry of Science and Technology. On the basis of his own investigations,
Kandler became a decided critic.
Awards and memberships
* 1971 German National
Academy of Sciences Leopoldina
The German National Academy of Sciences Leopoldina (german: Deutsche Akademie der Naturforscher Leopoldina – Nationale Akademie der Wissenschaften), short Leopoldina, is the national academy of Germany, and is located in Halle (Saale). Founded ...
* 1981 Dr. h.c. (
Ghent University
Ghent University ( nl, Universiteit Gent, abbreviated as UGent) is a public research university located in Ghent, Belgium.
Established before the state of Belgium itself, the university was founded by the Dutch King William I in 1817, when the ...
)
* 1982 Regensburger Botanische Gesellschaft
* 1982 Bergey Award
* 1983
Bavarian Academy of Sciences and Humanities
The Bavarian Academy of Sciences and Humanities (german: Bayerische Akademie der Wissenschaften) is an independent public institution, located in Munich. It appoints scholars whose research has contributed considerably to the increase of knowledg ...
* 1983 Mycological Society of India
* 1984 Hermann Weigmann-Medaille
* 1985 Dr. h.c. (
Technical University of Munich
The Technical University of Munich (TUM or TU Munich; german: Technische Universität München) is a public research university in Munich, Germany. It specializes in engineering, technology, medicine, and applied and natural sciences.
Establis ...
)
* 1989 Ferdinand-Cohn-Medaille
* 1991 Honorary member of
Deutsche Botanische Gesellschaft
* 1992
Order of Merit of the Federal Republic of Germany
The Order of Merit of the Federal Republic of Germany (german: Verdienstorden der Bundesrepublik Deutschland, or , BVO) is the only federal decoration of Germany. It is awarded for special achievements in political, economic, cultural, intellect ...
* 1994 Honorary member of Gesellschaft für Allgemeine und Angewandte Mikrobiologie
* 2005
Bavarian Order of Merit
The Bavarian Order of Merit (german: Bayerischer Verdienstorden) is the Order of Merit of the Free State of Bavaria. It is awarded by the Minister-President of Bavaria as a "recognition of outstanding contributions to the Free State of Bavaria ...
Selected publications
* Kandler, Otto (1950). Über die Beziehungen zwischen Phosphathaushalt und Photosynthese: I. Phosphatspiegelschwankungen bei Chlorella pyrenoidosa als Folge des Licht-Dunkel-Wechsels.
n the relationship between the phosphate metabolism and photosynthesis I. Variations in phosphate levels in ''Chlorella pyrenoidosa'' as a consequence of light-dark changes Zeitschrift für Naturforschung 5b, 423–43
pdf
*
*
*
*
*
*
*
*
*
* Kandler, O. (1998). The early diversification of life and the origin of the three domains: A proposal. pp. 19–31. In: Thermophiles: The keys to molecular evolution and the origin of life? (J. Wiegel & M.W. Adams eds.) Taylor and Francis Ltd. London, U
googlebooks*
* all publications
BAdW
Biographies and obituaries
* Müller, H.E. (1998). Portrait: "Otto Kandler und die moderne Mikrobiologie". ''Der Mikrobiologe. Mitteilungen des Berufsverbands der Ärzte für Mikrobiologie, Virologie und Infektionsepidemiologie'' 8(3), 38–4
BAdW
*
Sapp, J. (2009). ''The New Foundations of Evolution: On the Tree of Life''. Oxford, New York: Oxford University Press.
googlebooks
* (Bergey's International Society for Microbial Systematics
BAdW
* Tanner, W. (23 November 2017). Obituary: Professor Dr. Otto Kandler (1920–2017)
Deutsche Botanische Gesellschaft
* (typo in abstract: the three forms of life are Bacteria, Archaea, Eukarya).
*Tanner, W.;
Renner, S. (September 2018). Obituary - Prof. Dr. Dr. h.c. mult. OTTO KANDLE
BAdW* for further readin
BAdW
References
{{DEFAULTSORT:Kandler, Otto
1920 births
2017 deaths
20th-century German botanists
German microbiologists
Officers Crosses of the Order of Merit of the Federal Republic of Germany
Reich Labour Service members
German Army soldiers of World War II
German prisoners of war in World War II held by the United States
Ludwig Maximilian University of Munich faculty