title: Effects of chloramine on Bacillus subtilis deoxyribonucleic acid.
abstract: The lesions induced in Bacillus subtilis deoxyribonucleic acid (DNA) after treating bacterial cells (in vivo) and bacterial DNA (in vitro) with chloramine were studied biologically and physically. Single-strand breaks and a few double-strand scissions (at higher chloramine doses) accompanied loss of DNA-transforming activity in both kinds of treatments. Chloramine was about three times more efficient in vitro than in vivo in inducing DNA single-strand breaks. DNA was slowly chlorinated; the subsequent efficiency of producing DNA breaks was high. Chlorination of cells also reduced activity of endonucleases in cells; however, chlorinated DNA of both treatments was sensitized to cleavage by endonucleases. The procedure of extracting DNA from cells treated with chloramine induced further DNA degradation. Both treatments introduced a small fraction of alkali-sensitive lesions in DNA. DNA chlorinated in vitro showed further reduction in transforming activity as well as further degradation after incubation at 50 C for 5 h whereas DNA extracted from chloramine-treated cells did not show such  a heat sensitivity.
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002700:Chloramines / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000378:metabolism; D006358:Hot Temperature; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D002700:Chloramines; D004269:DNA, Bacterial; D003851:Deoxyribonucleases