title: Genetic determinants of active antibiotic-producing soil streptomycetes.
abstract: Plasmids or covalently closed circular (CCC)-DNA molecules are abundant in the genus Streptomyces, and have been suggested to be involved in the genetic control of the production of many antibiotics in these organisms. In this study, 21 active antibiotic-producing Streptomyces isolates were screened for their plasmid content by an alkaline lysis method which revealed the presence of a small plasmid DNA in the positive control Streptomyces lividans ATCC 35287, containing pIJ702 plasmid (5.65 kb in size). However, no low molecular weight plasmids were observed in the tested antibiotic-producing Streptomyces strains suggesting that antibiotic production in these strains is likely chromosomally encoded DNA. Treatment of 2 Streptomyces strains with 10 mM ethidium bromide (EB) resulted in the failure to produce aerial mycelia and antibiotic activity.
authors.affiliation: Dept. of Biological Sciences, Jordan Univ. of Science and Technology, Irbid, Jordan.
authors.forename: I
authors.initials: I
authors.lastname: Saadoun
authors.forename: F
authors.initials: F
authors.lastname: al-Momani
authors.forename: A
authors.initials: A
authors.lastname: Elbetieha
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D000898:Antibiosis / Q000235:genetics; D002876:Chromosomes, Bacterial / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D012988:Soil Microbiology; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial