Which microbiologist discovered bacteriophage lambda while studying Escherichia coli in 1950?

Esther Lederberg discovered bacteriophage lambda while studying Escherichia coli in 1950.

Bacteriophage lambda is a virus that infects E. coli. It became a crucial model in molecular biology because it can follow two different pathways: it may replicate and destroy its bacterial host, or it may integrate its genetic material into the host chromosome in a dormant state called lysogeny.

Lederberg’s discovery helped researchers investigate gene regulation, viral genetics and the relationship between bacterial cells and their viruses. She also developed replica plating with Joshua Lederberg, a technique that transfers bacterial colonies to new growth surfaces while preserving their positions.

Her work is often overshadowed by her former husband’s Nobel recognition. Joshua Lederberg shared the 1958 Nobel Prize in Physiology or Medicine, but Esther Lederberg did not receive that prize.