Anaerogenic Fermentation with Paratyphoid Bacilli

Abstract

1. Anaerogenic races ofB. paratyphosusB are stable in ordinary artificial culture.2. Aerogenic variants of anaerogenic strains can be produced (though the anaerogenic strain persists) by growth in dextrose or mannitol with a relatively large amount of sodium formate. Such variants can then produce gas from all the other “sugars” fermentable byB. paratyphosusB.3. Failure to produce gas from sugars by anaerogenic races is due to deficiency in the power of breaking down the formate produced in the first stage of fermentation.4. A mixture of dextrose and formate in peptone water reveals the latent capacity for gas production in anaerogenic races ofB. paratyphosusB. This confirms the observations of Grey (1914, 1920, 1924).Since this work was done, we have seen the paper of Pot and Tasman (1932) in which they succeed in isolating aerogenic variants from anaerogenic cultures ofB. paratyphosusB by continued cultivation in 2 per cent. calcium formate, in a somewhat similar manner as we have done with the mixture of dextrose and sodium formate.