Microbial ecology of Bacillus thuringiensis. V. Selective medium for Bacillus thuringiensis vegetative cells

Bacillus thuringiensis vegetative cells were capable of growing on a defined media containing acetate or citrate. In contrast, no growth of this bacterium was detected on these media when spores were used as the inocula. Based on the assimilation tests of organic compounds, a selective medium for vegetative cells (BTV medium) was devised for B. thuringiensis subsp. thuringiensis and subsp. morrisoni. Composition of the medium was as follows : NaNO3, 1.0g; KH2PO4, 1.0 g; MgSO4·7H2O, 0.5 g; KCl, 0.2 g; sodium acetate, 1.0 g; sodium citrate, 3.0 g; Difco purified agar, 15.0 g; polymyxin B, 5 mg; deionized water, 1, 000 ml; pH 7.0.