INHIBITION OF YEAST AND MOLD GROWTH DURIN G QUANTITATIVE-ANALYSIS OF BACTERIA

Culture media are described which allow cultivation of bacteria and si multaneous inhibition of yeast and mold growth. Sabouraud dextrose-, P late count- or China blue lactose agar containing 500 mug/ml natamycin are suitable. Natamycin and culture medium could be autoclaved togeth er for 15 min at 121-degrees-C and subsequently stored for 3 months at 4-degrees-C without loss of the inhibitory activity. Because of the h eat and light sensibility of natamycin, the media should be melted onl y once after autoclaving, and should be stored in the dark. These cult ure media can be used for enumeration of bacteria counts, even if the samples to be analyzed contain high numbers of fast growing molds like Mucor.