A survey of Streptomyces species for covalently closed circular (ccc) DNA using a variety of methods

The Loss of a Large DNA Fragment is Associated with an Aerial Mycelium Negative (Amy-) Phenotype of Streptomyces cattleya

“…It is feasible that the total absence of the 5.6 kb sequence contained in pTG17 in some of these strains could be due to plasmid loss, although a plasmid has yet to be found in this species (Kirby et al, 1982). Extrachromosomal DNA observed in the type I1 mutants could be the result of a deletional event on such a plasmid, br be the product of the deletion and excision of hybridizing sequences from the chromosome.…”

“…Amy-clones were grown on Malt 3 agar (Kirby et al, 1982) at 30 "C for 2 d in a grid pattern before transfer to nitrocellulose filters placed on a fresh Malt 3 plate. The colonies were allowed to grow up on the filters for 2 d at 30 "C. Colony hybridization was carried out using a modification of the method of Schrempf (1982).…”

Isolation and characterization of a plasmid, pSLG3, from Streptomyces lavendulae-grasserius

“…Many plasmids of different Mr and copy number have been isolated from antibiotic-producing streptomycetes, and a possible involvement of plasmids in antibiotic production has been suggested by a number of workers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”