Experiments with micro-organisms and human cell cultures in the Zond 5 and Zond 7 flights.

Lysogenic strains of Escherichia coli were exposed to space conditions aboard the flight of Zond 5 and Zond 7. Space flight factors appeared to affect the state of episome systems of bacteria, as judged by data obtained with F-Lac+ donor cells which also carried genetic markers for threonine and leucine. Observations on phage induction are discussed and compared with results obtained aboard Biosatellite 2.