RT Journal Article SR Electronic(1) A1 Akagawa, H. A1 Okanishi, M. A1 Umezawa, H.YR 1975 T1 A Plasmid Involved in Chloramphenicol Production in Streptomyces venezuelae: Evidence from Genetic Mapping JF Microbiology, VO 90 IS 2 SP 336 OP 346 DO https://doi.org/10.1099/00221287-90-2-336 PB Microbiology Society, SN 1465-2080, AB SUMMARY: To test the hypothesis that chloramphenicol production in Streptomyces venezuelae depends on the presence of a plasmid, mapping analysis was carried out by using eight markers in addition to chloramphenicol production and melanoid pigment formation. The sequence of the eight markers was determined on a circular linkage map as follows: -his-ade-str-leu-lys-met-ilv-pro-(his-). This sequence resulted in the frequency of quadruple crossover (q.c.o.) recombinants having the lowest value, 3·2 to 4·9 %. However, the character of chloramphenicol non-production, which was obtained by incubating mycelia with acriflavin, was not located on this linkage map; more than 15 % q.c.o. recombinants would have been required to explain the results. From these results and other tests, it is concluded that chloramphenicol production is controlled by a plasmid. This plasmid appeared to be non-transferable in conjugation., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-90-2-336