Sydney Kustu

Sydney Govons Kustu (March 18, 1943 – March 18, 2014) was an American biologist and a professor of biochemistry at University of California, Berkeley. She is known for her pioneering research on the regulation of Nitrogen metabolism in bacteria.

Academic career At the early age of 15, she entered Radcliffe College, the all-female counterpart to Harvard, receiving her Bachelor of Arts degree in General Studies in 1963, making her among the first females to graduate from Harvard. She then studied as a technician with Saul Roseman at the University of Michigan, and received her doctorate in biochemistry from UC Davis in 1970, studying under Jack Preiss. She performed postdoctoral research at the UC Berkeley in the laboratory of Giovanna Ferro-Luzzi Ames. In 1973, UC Davis hired her as an assistant professor, and she was promoted to full professor in 1984. She was subsequently recruited to UC Berkeley in 1986, from which she retired in March 2010 and received Emeritus status.

Scientific contributions

Among her contributions to microbial genetics and physiology, she worked on bacterial genes and how they are regulated due to the availability of nitrogen-containing compounds from their environment. She had found that strains of Salmonella typhimurium selected for utilization of D-histidine in place of L-histidine were frequently the result of mutations affecting glutamine synthetase (GS), a central enzyme in the pathways of nitrogen utilization. A bottle of research-grade sodium azide, likely obtained from her former laboratory, had been left on a table with its lid tightly secured. The unusual nature of her suicide prompted a major emergency response operation to evacuate the landmarked Julia Morgan-designed building. Sodium azide is a commonly used research chemical, used as a biocide to prevent unwanted bacterial growth in stock chemicals, as well as an inhibitor of cytochrome oxidase for studying the influence of oxidative respiration in gram-negative bacteria.