SUMMARY: Upon repeated subculture in media of gradually increasing pH value a strain of developed the ability to grow under strongly akaline conditions. Organisms with the highest alkali resistance could grow at pH 10·3, and stocks of intermediate resistance were also obtained. When growing on alkaline agar, resistant bacteria underwent marked morphological changes. In liquid media, the bacteria retained the ability to synthesize lecithinase. Resistance was not lost upon several transfers on a neutral medium.

Resistant bacteria when growing in alkaline media caused a rapid decrease in pH value. A similar pH decrease was caused by sensitive bacteria in media of the highest degree of alkalinity in which they could grow. The decline of pH value accompanied, but did not precede, growth; acid production by the resistant bacteria does not appear to be a primary mechanism of resistance.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error