CHARACTERIZATION OF RESTRICTION ENDONUCLE ASES FROM VIBRIO-CHOLERAE NON-O1

Fourteen restriction endonucleases (ENases) were found by screening of 118 O antigen reference strains of Vibrio cholerae. Ten of these ENas es were partially purified and classified into eight specificity categ ories. All of them were isoschizomers of already-known ENases. It is o f interest that the isoschizomer of EcoRI ENase designated VchO2I was found in V. cholerae O2, since VchO2I, as well as EcoRI, shows high ac tivity at pH 8 approximately 9, and most V. cholerae strains can grow well in this pH range.