Hans Krebs lost his German job in 1933 and found his cycle in England
Dismissed by the Nazi regime in 1933 because of his Jewish ancestry, Hans Krebs was quickly rescued by a Cambridge biochemist. German officials let him take his lab equipment along, including a special oxygen-measuring device. With it he went on to map the citric acid cycle, the chain of reactions that powers oxygen-breathing cells.
Krebs was born in 1900 in Hildesheim, the son of an ear, nose and throat surgeon. Conscripted into the German army in 1918, six months before finishing school, he passed an emergency diploma exam with marks so high he suspected the examiners had gone easy on him. The war ended two months later. He trained in medicine, but by his mid-twenties had decided on research rather than practice.
In 1926 he became an assistant to Otto Warburg in Berlin, and after four years and 16 papers Warburg told him to move on. At a clinic in Freiburg, while caring for about 40 patients, he and his student Kurt Henseleit discovered within a year how the body makes urea, the ornithine or urea cycle. That work made his name. Then came the civil service law of 1933, and dismissal. Frederick Gowland Hopkins persuaded Cambridge to take him in, with Rockefeller Foundation money. The manometer Warburg had designed for measuring oxygen use in thin tissue slices, which the Nazi authorities had let him export, became the basis of his next work.
In 1935 Sheffield offered him a bigger laboratory and twice the salary, and he stayed 19 years, founding its biochemistry department. There he pieced together the citric acid cycle, the sequence that lets cells extract far more ATP from food than anaerobic processes can, earning the 1953 Nobel Prize in Physiology or Medicine. His Medical Research Council unit grew so large that locals called it Krebs's Empire. With Hans Kornberg he later found the glyoxylate cycle, a variant used by plants, bacteria and fungi.
He moved to Oxford in 1954 and formally retired in 1967, but promised the Biochemical Journal he would keep them busy, and went on to publish over 100 more papers. He met his wife Margaret in Sheffield; their son John became an Oxford ornithologist and a member of the House of Lords. Krebs died in Oxford in 1981.
Source: Hans Krebs (biochemist)
