DEVELOPMENT OF GENE-TRANSFER METHODS FOR RUBRIVIVAX-GELATINOSUS S1 - CONSTRUCTION, CHARACTERIZATION AND COMPLEMENTATION OF A PUF OPERON DELETION STRAIN

Gene transfer systems were developed in Rubrivivax (Rx.) gelatinosus S 1. First, a system for conjugative transfer of mobilizable plasmids fr om Escherichia coli to Rx. gelatinosus S1 was established. Secondly, o ptimal conditions for the transformation of Rx. gelatinosus S1 by elec troporation were determined. A Delta puf strain was constructed. Compl ementation with the puf operon from a wild-type strain cloned in a rep licative plasmid restored photosynthetic growth. Two insertion strains were also selected. All the strains constructed were green, due to a change in carotenoid content. Characterization of these strains provid es genetic evidence for a ''superoperon'' organization in this bacteri um.