Effect of azalomycin F on bacteria.

It has previously been reported that azalomycin F could induce permeability changes in Candida albicans causing loss of cell constituents and inhibition of substrate uptake which resulted in the death of the organism1). The present report is concerned with the effect of the antibiotic on bacteria. Methods and Results Azalomycin F inhibited the growth of Bacillus subtilis PCI 219 at concentrations of 3.0 mcg/ml in Stephanson-Whetham me dium and of 3.0--6.0mcg/ml in nutrient broth, whereas it failed to inhibit the growth of Escherichia coli NIHJ even at concentra tions as high as 200 mcg/ml in both media. In the presence of the antibiotic viable cells of B. subtilis were rapidly reduced in number during the incubation indicating the drug action is bactericidal (Table 1). The release of soluble constituents from washed cells by the action of azalomycin F was then examined in the following way2). The organism was grown overnight in nutrient broth. Cells were harvested by centrifugation, washed thoroughly in phy siological saline, and finally suspended in 1% (w/v) saline to give a suspension containing between 2 and 5 mg dry weight Table 1. Activity of azalomycin F against the cell replication of Bacillus subtilis in natural and synthetic media D ose