title: Induction of resistance to novobiocin in the novobiocin-producing organism Streptomyces niveus.
abstract: During growth of Streptomyces niveus wild-type in the novobiocin production medium CDM the resistance of mycelia to novobiocin rises from about 25 micrograms/ml to over 200 micrograms/ml. (S. lividans, a novobiocin-sensitive strain, is resistant to approx. 10 micrograms/ml novobiocin.) The initial period of low level resistance extends from the time of inoculation of the culture until approx. 70 h when the culture is still in the growth phase. High level resistance is initiated before the start of novobiocin production and rises rapidly to a maximum level beyond the end of the growth phase. The rise in pH of the unbuffered CDM medium which occurs during S. niveus fermentation was shown not to be the cause of the change in novobiocin resistance. However, mycelia-free CDM from S. niveus cultures expressing high level novobiocin resistance was shown to contain a factor which induced high level novobiocin resistance in germinating S. niveus spores. Kinetic studies revealed that the inducer first appears in the culture medium before the switch to high level resistance begins and reaches its highest concentration before resistance reaches its maximum level.
authors.affiliation: Department of Genetics and Microbiology, Donnan Laboratories, University of Liverpool, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Hoggarth
authors.forename: K E
authors.initials: KE
authors.lastname: Cushing
authors.forename: J I
authors.initials: JI
authors.lastname: Mitchell
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie
mesh_terms: D003470:Culture Media; D004352:Drug Resistance, Microbial; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009675:Novobiocin / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology*; D013171:Spores, Bacterial; D013302:Streptomyces / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D003470:Culture Media; D009675:Novobiocin