Recovery in the presence of chloramphenicol of Escherichia coli B(H) irradiated with ultra-violet light

Abstract

IT has been observed in several instances that protein synthesis is involved in the effects produced in micro-organisms by irradiation with ultra-violet light, as has been shown by changes during post-irradiation incubation. Witkin¹ and Doudney and Haas² obtained results which suggested the importance of protein synthesis in the induction of mutation by Salmonella typhimurium and Escherichia coli respectively, Gillies and Alper³ in the recovery of Escherichia coli B and Harold and Ziporin⁴ in the synthesis of deoxyribonucleic acid in Escherichia coli B. We have found that the synthesis of ribonucleic acid in Escherichia coli B(H)—a strain obtained from Prof. Itaru Watanabe, Virus Laboratory, University of Kyoto, which has a specific property in bacteriophage infection⁵—is completely dependent on the protein synthesis which occurs during the first 30 min. of post-irradiation incubation⁶. We have therefore investigated the biological and chemical nature of protein produced in this way, and some of the results are described here.