Counting living microorganism cells in food - using culture medium contg 2,3,5- triphenyl-tetrazolium chloride to prevent colony diffusion

摘要

A culture medium useful in counting living microorganism cells in food using an agar medium is prepd. by adding 2,3,5-triphenyltetrazolium chlorie to an aq. soln. of the culture medium as a colony-diffusion preventing agent. An example, of teh compsn. of the medium: 2.5 g./l. yeast extract, 5 g./l. peptone, 1 g./l. glucose, 0.04 g./1. 2,3,5-triphenyltetrazolium chloride and 15 g./l. of agar. 2,3,5-Triphenyltetrazolium chloride does not inhibit growth of bacteria forming no diffused colony but prevents specifically colony formation of bacteria forming diffused colonies. A culture plate contg. no diffused colony can be obtd. and more exact count of living microorganism cells is enabled by use of the culture medium.