Aeration of Bacillus anthracis in submerged fermentation.

An investigationi was undertaken to determine the oxygen absorption rates of a submerged culture of Bacillus anthracis at all stages of its growth cycle. The determination of oxygen absorption rates of a pathogenic fermentation such as this by analysis of the exhaust gases seemed to present fewer technical difficulties than did those methods that depended upon polarographic determination of dissolved oxygen. Some results of this investigation are reported here. A survey of the literature would indicate that it is not usually practicable to determine oxygen absorption rates of a submerged fermentation from analysis of the exhaust gas and a material balance. The difficulty arises, of course, from the fact that, when percentage absorption is low, oxygen analyses and other measurements must be very precise to be significant. Finn (1954) states that absorption of oxygen seldom exceeds 2 per cent in fermentation processes. The data in table 1 seem to support this assertion. However, Hromatka and Ebner (1951) used analyses of exhaust gases to study the oxygen uptake of a submerged vinegar fermentation where air rates were low. Hoover et al. (1954) measured the oxygen uptake of a "balanced flora" by analyzing the gas phase for the percentage of oxygen and suggested that the method might be useful in most aerobic fermentations. Maxon