“…Ferrari et al (1983) utilized an integrable plasmid, pJHlOl, to clone and map several genes in B. subtilis• A similar plasmid, pHV32, was used for insertional mutagenesis in B. subtilis ; both pHV32 and pJHlOl yielded equivalent results for the generation of auxotrophic mutations (Ferrari et al, 1983). Additional integrable plasmids have been utilized for molecular cloning and genomic analysis in Gram-positive systems (Fahnestock et al,, 1986;Gryczan and Dubnau, 1982;LaFauci et al, 1986;Niaudet et al, 1982;Pozzi and Guild, 1985;Prozorov et al, 1983;Vasseghi and Claverys, 1983;Young, 1983). Integrable plasmids have found extensive use because they are genetically and physically wellcharacterized, and because they replicate in E. coli.…”