The effect of rice powder on the growth of cultures of Endamoeba histolytica.

Abstract

Summary 1. The effects of various amounts of rice powder were studied on the growth of 3 strains of E. histolytica cultured with a mixed bacterial flora. 2. The addition of rice flour increased the amount and duration of amebic growth. 3. The length of survival of the ameba cultures was directly related to the rice flour content of the medium. 4. There was an optimal amount of rice powder for the most abundant growth of amebae. 5. In cultures containing the largest amounts of rice powder, the lag phase of amebic growth was prolonged and there was a relative depression of the fold increase of the populations and in the rates of multiplication. 6. The addition of rice powder produced no gross changes in the bacterial flora growing with each strain. 7. Within 48 hours after inoculation, there was a fall in the pH of the cultures containing the largest amounts of rice. 8. Amebic growth accelerated the disintegration of rice particles into granules and the disappearance of the latter from the culture medium.