Abstract
On agar-plate cultures of B. coli stored at 18-20°C. for one week, a mucoid outgrowth from several colonies was observed. Subcultures from this mucoid structure indicated that the mucoid characteristic could be maintained only if cultures were incubated at this temperature. Revis 1 noted that mucoid forms of B. coli obtained by storage of organisms in soil would retain this characteristic if incubated at 20°C. but reverted to the more typical form if incubated at 37°C. Smith's 2 strain of mucoid B. coli from bovine sources retained its mucoid consistency when stored at 4.5°C. if drying out did not take place.
Our mucoid organisms were physiologically stable. Stains revealed a zoogloeic structure similar to that reported by Revis. 1
To determine the influence of temperature on the persistence of the mucoid characteristic, transfers were made from the mucoid growth of 3 strains of B. coli on 1% glucose-agar plates. These were incubated at various temperatures for a period of 5 days before the type of growth was recorded as in Table I.
The marked correlation between incubative temperature and mucoid growth of B. coli indicates that the thermal factor is important in the production of mucoid dissociants of this organism.
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