“…In the early 1970s, studies following three avenues of research were initiated. These were the biochemical characterization of non-OTC-producing mutants and mapping of the OTC genes (180,200), characterization and persistence of S. rimosus phages (104,107,193,225), and genetic and physical characterization of circular and linear S. rimosus plasmids (31,41,72,80,201,212).…”