ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The growth of Clostridium acetobutylicum was studied by three ways. 1. In batch fermentation, referred to as the control. 2. Fermentation in dialysis which permits elimination of all the products of metabolism: acids, solvents and gases. In order to test the toxic effect of acids, cultures were dialysed against 2 g l-1 acetic acid or 2 g l-1 butyric acid. 3. To test the toxic effect of gases only, batch fermentations were carried out under vacuum or with a continuous bubbling of nitrogen. The first method resulted in a productivity of 1.2 g l-1 dry cell weight and a maximal specific growth rate of 0.2 h-1; the second, 20 g l-1 dry cell weight and a constant maximum specific growth rate (μ=0.39 h-1) between 14 and 20 h. The toxic effect of acetic and butyric acids, starts at low concentrations and about 4 g l-1 of both acids results in a decrease of 50% of maximal specific growth rate. The third series of experiments showed that gases produced by the bacteria have a high toxic effect, comparable to that of 5 g l-1 of acid.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00253034
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