WORLD OF MICROBIOLOGY AND IMMUNOLOGY Dubos, René167•
nature and the environment, an interplay which is as old as life
itself and which is the mechanism for creation on Earth.”
Dubos was born in Saint-Brice-sous-Foret, France, the
only child of Georges Alexandre and Adeline Madeleine de
Bloedt Dubos. Young Dubos spent his early years in the farm-
ing villages of Ile-de-France, north of Paris. Amongst the
rolling hills and agricultural fields, Dubos developed a keen
appreciation for the influence of landscape on the human
spirit, a subject that would come to dominate his thoughts in
later years. A bout with rheumatic fever at the age of ten both
restricted Dubos’s physical activity and enhanced his contem-
plative nature. When Dubos was 13, his father moved the fam-
ily to Paris to open a butcher shop; a few months later,
Georges Dubos was called to military service in World War I,
leaving his wife and young son in charge of the business.
Despite the best efforts of mother and son, the shop did poorly
and the family had a difficult time getting by. Upon complet-
ing high school at the College Chaptal in 1919, Dubos had
hoped to study history at the university, but the death of his
father from head injuries suffered at the front forced him to
stay closer to home to look after his mother. Dubos was
granted a scholarship to study agricultural science at the
Institut National Agronomique in Paris, receiving his bachelor
of science degree in 1921. He spent part of the next year as an
officer trainee in the French Army, but was soon discharged
because of heart problems.
In 1922, Dubos was offered the job of assistant editor at
a scholarly journal called International Agriculture
Intelligence, published by the International Institute of
Agriculture, then part of the League of Nations in Rome. Not
long after he arrived in Italy, Dubos came across an article on
soil microbes written by the Russian bacteriologist Sergei
Winogradsky, who was then associated with the Pasteur
Institute in Paris. Winogradsky’s contention that microbes
should be studied in their own environment rather than in
pure, laboratory-grown cultures so intrigued Dubos that he
resolved to become a bacteriologist. “This is really where my
scholarly life began,” he told John Culhane in an interview for
the New York Times Magazine.“I have been restating that idea
in all forms ever since.” Soon after, Dubos happened to meet
the American delegate to the International Institute of
Agriculture, who convinced him to pursue graduate studies in
the United States.
In order to finance his trip, Dubos translated books on
forestry and agriculture and gave guided tours of Rome to for-
eign visitors. He eventually set sail for New York in 1924.
During the crossing, Dubos ran into Selman Waksman, head of
the soil microbiology division of the State Agricultural
Experiment Station at Rutgers University in New Jersey (a
man the aspiring scientist had guided around Rome some
months before). After the ship docked in New York, Waksman
introduced Dubos to his colleagues at Rutgers University,
helping the young man secure a research assistantship in soil
microbiology. While serving as an instructor in bacteriology
over the next three years, Dubos completed work on his doc-
torate. His thesis, published in 1927, focused on the ways in
which various soil microorganismswork to decompose cellu-
lose in paper.Upon completing his work at Rutgers, Dubos left for the
University of North Dakota at Fargo to accept a teaching posi-
tion in the department of microbiology. Soon after he arrived,
however, Dubos received a telegram from the Rockefeller
Institute for Medical Research in New York City offering him
a fellowship in the department of pathology and bacteriology.
Dubos immediately packed his bags, in part because the offer
involved work on a project begun by Rockefeller bacteriolo-
gist Oswald T. Avery. Avery and his colleagues had been
searching for a substance that could break down the semi-cel-
lulose envelope which protects pneumococci bacteria, the
microorganisms responsible for lobar pneumoniain human
beings, from attack by the body’s defense mechanisms.
Dubos’s bold assertion that he could identify an enzyme capa-
ble of decomposing this complex polysaccharide capsule with
minimal damage to the host had evidently impressed Avery.
With the exception of a two-year period in the early 1940s
when he served on the faculty at Harvard Medical School,
Dubos remained at the Rockefeller Institute, renamed
Rockefeller University in 1965, for the next 44 years.
Guided by the studies of renowned bacteriologist Louis
Pasteur, who maintained that any organic substance that accu-
mulated could be broken down by natural energy, Dubos spent
his first two years at the Institute searching fields, bogs, and
swamps for a bacterium or fungus that could attack and decom-
pose the tough polysaccharide coat surrounding pneumococci
bacteria. Unlike other scientific investigators, who used
enriched laboratory solutions to cultivate bacteria and force
them to produce enzymes, Dubos concocted a solution rich in
capsular polysaccharide, which he spread over a variety of
soils. In 1929, he succeeded in isolating a swamp-dwelling
bacillus which, because of its need for nourishment in an
energy-starved environment, had been compelled to produce
an enzyme capable of decomposing the polysaccharide capsule
and digesting the pneumococci within. The following year
Dubos was able to demonstrate the value of this particular
enzyme in fighting pneumococcal infections in both animals
and humans. The discovery confirmed Dubos’s belief that soil
bacteria were an important source of anti-infectious agents,
inspiring him to search for other disease-fighting microbes.
In 1939, Dubos announced the discovery of a substance
called tyrothricin, which had proved effective in fighting
staphylococcus, pneumococcus, and streptococcus infections.
Produced by the soil microorganism Bacillus brevis,
tyrothricin was later found to contain two powerful chemicals,
gramicidin and tyrocidine, which, though too toxic for inges-
tion, found widespread application in the treatment of external
conditions, such as infectious lesions in humans and udder
infections in cows. Dubos’s groundbreaking work prompted
scientists from around the world to conduct a wide-ranging
search for antibiotic substances in natural environments. This
ultimately resulted in a reexamination of the therapeutic prop-
erties of penicillin—first discovered in a bread moldten years
earlier by Alexander Fleming—and led to the isolation of a
variety of new antibiotics, including streptomycin and the
tetracyclines.
The death of Dubos’s first wife, Marie Louise Bonnet,
from tuberculosis in 1942 had a profound effect upon the sci-womi_D 5/6/03 2:09 PM Page 167