Biological nitrogen fixation was discovered by German agronomist Hermann Hellriegel and Dutch microbiologist Martinus Beijerinck. A microbiologist (from Greek ) is a scientist who studies microscopic life forms and processes. Proper identification requires a microbiologist or mycologist. Sharon Peacock is a British microbiologist and professor. Comandon was a trained microbiologist specializing in syphilis research. Neter is an American microbiologist and physician. Zena Maria Cardman (born October 26, 1987) is an American microbiologist and NASA astronaut. Cholera toxin was discovered in 1959 by Indian microbiologist Sambhu Nath De. The contamination claim was made by microbiologist Dr. John Gerdes. His brother was the microbiologist and writer John Postgate FRS. This process was discovered by the Russian microbiologist Sergei Winogradsky. These drugs were later renamed antibiotics by Selman Waksman, an American microbiologist, in 1942. It is named after Bernhard Fischer, a German microbiologist. Serotypes were discovered by the American microbiologist Rebecca Lancefield in 1933. Hayek's son, Laurence Hayek (1934 - 2004) was a distinguished microbiologist.