Dnacins, new antibiotics. I. Producing organism, fermentation, and antimicrobial activities

Dnacins are new antibiotics produced by an actinomycete, strain No. C-14482 (N-1001). The characteristic features of the organism are: the formation of coremia on solid media, production of rod-shaped motile spores with peritrichous flagella from mature aerial mycella, fragmentation of the mature organism (at later stage of growth) in liquid media in which some fragmented elements have motility, lysozyme resistance, meso-diaminopimelic acid in the cell wall, and a guanine-cytosine content of 71 +/- 1 mol%. The organism has been designated as Nocardia sp. No. C-14482 (N-1001). Dnacins show strong activity against various GRam-negative, Gram-positive, and acid-fast bacteria, but slight activity against fungi. The antibiotics hardly affect the growth of Escherichia coli K-12 under anaerobic condition even at concentrations more than five times that of the minimum inhibitory concentrations under aerobic conditions.