Decreased DNA damage by acid and increased repair of acid‐damaged DNA in acid‐habituated Escherichia coli

Abstract
A study of the conjugal transfer of ColV,I‐K94 tn10 from acid‐treated donors suggested that acid‐habituated recipients repair acid‐damaged plasmid DNA better than those that are not habituated. The presence of an increased repair activity for acid‐damaged DNA in habituated cells was confirmed by isolating pBR322 from acid‐treated organisms; habituated cells produced more transformants when transformed by it than did non‐habituated ones. Additionally, agarose gel electrophoretic studies of pBR322 DNA isolated from acid‐damaged cells and tests of its transforming activity both indicated that plasmid DNA in habituated cells is less damaged by extreme acidity than is that in non‐habituated organisms.