C. B. van Niel

Cornelius Bernardus Van Niel
Born	(1897-11-04)November 4, 1897 Haarlem
Died	Carmel, California
Nationality	USA, Netherlands
Fields	Microbiology
Institutions	Hopkins Marine Station
Alma mater	TU Delft
Doctoral advisor	Albert Kluyver
Doctoral students	Roger Stanier
Known for	Chemistry of photosynthesis
Notable awards	National Medal of Science (1963) Leeuwenhoek Medal (1970)
Signature

Cornelius Bernardus (Kees) Van Niel (November 4, 1897, Haarlem – March 10, 1985, Carmel, California) was a Dutch-American microbiologist. He introduced the study of general microbiology to the United States and made key discoveries explaining the chemistry of photosynthesis.

Early life

In 1923, Cornelius Van Niel married Christina Van Hemert, graduated in chemical engineering at Delft University and became an assistant to Albert Jan Kluyver, who had initiated the field of comparative biochemistry. In 1928 he wrote his PhD dissertation ('The Propionic Acid Bacteria') after which he left for the United States to continue his work at the Hopkins Marine Station of Stanford University.

Work and discoveries

Photosynthesis (1931)

By studying purple sulfur bacteria and green sulfur bacteria he was the first scientist to demonstrate that photosynthesis is a light-dependent redox reaction in 1931, in which hydrogen from an oxidizable compound reduces carbon dioxide to cellular materials. Expressed as:

2 H₂A + CO₂ → 2A + CH₂O + H₂O

where A is the electron acceptor. His discovery predicted that H₂O is the hydrogen donor in green plant photosynthesis and is oxidized to O₂. The chemical summation of photosynthesis was a milestone in the understanding of the chemistry of photosynthesis. This was later experimentally verified by Robert Hill.

In a nutshell, van Niel proved that plants give off oxygen as a result of splitting water molecules during photosynthesis, not carbon dioxide molecules as thought before.

Bacterial taxonomy

Van Niel also played a key role in the development of Bacterial taxonomy. In 1962, Van Niel in collaboration with Roger Y. Stanier defined prokaryotes as cells in which the nuclear material is not surrounded by a nuclear membrane, a definition that is still used to date.

Teaching

Shortly after his arrival at Hopkins Marine Station, Van Niel developed a course in general microbiology which was to become widely influential. During its run from 1938 to 1962, the course drew students from around the world, and included several accomplished scientists among its alumni, including Esther Lederberg and Allan Campbell. and Arthur Kornberg, the recipient of the 1959 Nobel prize for DNA synthesis.

Scientific legacy and awards

Van Niel was the first biologist to receive the American National Medal of Science; he was awarded the 1963 Medal in Biological sciences for "his fundamental investigations of the comparative biochemistry of microorganisms, for his studies of the basic mechanisms of photosynthesis, and for his excellence as a teacher of many scientists." Additional awards include:

• 1955: Marjory Stephenson Prize of the Society for General Microbiology
• 1966: Charles F. Kettering Award of the American Society of Plant Biologists
• 1967: Rumford Prize
• 1970: Leeuwenhoek Medal

In 1950 Van Niel became a correspondent of the Royal Netherlands Academy of Arts and Sciences.

External links

• National Academies Press Biography
• Memorial resolution at Stanford University.
• Anecdote about C. B. Van Niel at Hopkins Marine Station, Monterey, CA