title: Conjugal transfer of nisin plasmid genes from Streptococcus lactis 7962 to Leuconostoc dextranicum 181.
abstract: Acriflavine-generated mutants of Streptococcus lactis 7962 with various combinations of plasmid molecular masses were screened for nisin production. Nisin was produced by both the wild type and mutants that contained a 17.5-megadalton plasmid, which was obscured by chromosomal fragments. No nisin was produced by plasmid-free mutants. Sucrose fermentation and nisin production were simultaneously expressed. A transconjugant obtained from nisin-producing donor S. lactis 7962 and recipient Leuconostoc dextranicum 181 was a "supernisin" producer. The L. dextranicum Nis+ transconjugant was resistant to S. lactis 7962 phage and vancomycin (greater than 1,000 micrograms/ml), and it contained an extra 17.5-megadalton plasmid.
mesh_terms: D002499:Centrifugation, Density Gradient; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D004352:Drug Resistance, Microbial; D004587:Electrophoresis, Agar Gel; D005285:Fermentation; D005798:Genes, Bacterial; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism; D007934:Leuconostoc / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009561:Nisin / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D010641:Phenotype; D010957:Plasmids; D013395:Sucrose / Q000378:metabolism; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D004269:DNA, Bacterial; D009561:Nisin; D013395:Sucrose; D014640:Vancomycin