THE INHIBITION OF PHYTOMONAS MALVACEARA IN CULTURE MEDIA CONTAINING SUGARS

Abstract

Phytomonas malvaceara fails to grow in culture media containing glucose, maltose, lactose, galactose, or levulose and various nitrogenous compounds when sterilized at 122[degree] C. for 15 min. This is not due to lack of ability to assimilate the various sugars but to chemical changes caused by the high temp. of sterilization. Inhibition depends on the amount of peptone, sugar, and phosphate present; the reaction of the solution during the heating period; and the temp. and length of the period of sterilization. It is not due to changes in pH during sterilization. Inhibition occurs in culture media which, in the absence of the sugars, are suitable for growth. It is concluded that inhibition is due to conversion of the nitrogen compound into a form which is not suitable for assimilation by some species of bacteria.