title: Crucial factor for increasing the conjugation frequency in Streptomyces netropsis SD-07 and other strains.
abstract: Streptomyces netropsis SD-07, the producer of novel polyene macrolide antifungal antibiotics, was isolated from soil. For the investigation of the functions of its biosynthesis genes and regulation mechanisms, a genetic operating system is necessary. In this study, we successfully transferred the plasmid DNA of pSET152 from the methylation deficient donor, Escherichia coli ET12567/pSET152/pUZ8002, to S. netropsis SD-07 by conjugation and evaluated the crucial factors influencing the conjugation frequency. Ca(2+) ions in presence the conjugation media may increase the conjugation frequency by 1000-10 000 times than Ca(2+) ions absence in the same conjugation media, and 10-100 time higher than Mg(2+) ions. Similar results (increasing the conjugation frequency by 10-100 times when media containing 60 mM CaCl2 ) were also obtained from the conjugation between E. coli ET12567 and Streptomyces coelicolor, S. lavendulae, S. venezuelae, despite their conjugation media were different (MS, CM, GS). So, CaCl2 concentration is a crucial factor for increasing the conjugation frequency, and the suitable concentration may probably be 60 mM. In addition, synthetic medium containing a small amount of organic nitrogen source may benefit increasing the conjugation frequency. These findings could be valuable for the development of a practical method for achieving conjugation in other Streptomyces spp.
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China.
authors.forename: Xian-Kun
authors.initials: XK
authors.lastname: Wang
authors.forename: Jian-Ling
authors.initials: JL
authors.lastname: Jin
mesh_terms: D002118:Calcium / Q000378:metabolism; D002122:Calcium Chloride / Q000378:metabolism; D003227:Conjugation, Genetic / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D008345:Manganese / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
chemical_list: D008345:Manganese; D002122:Calcium Chloride; D009584:Nitrogen; D002118:Calcium
keywords: Ca2+ ion; Streptomyces netropsis; conjugation; polyene macrolide antifungal antibiotics