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Inhibition of acetate and propionate formation upon aeration of resting cells of the anaerobic Propionibacterium shermanii: Evidence on the PASTEUR reaction

✍ Scribed by Dr. A. C. Schwartz; Barbara Mertens; K. W. Voss; H. Hahn


Book ID
102909171
Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
664 KB
Volume
16
Category
Article
ISSN
0233-111X

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✦ Synopsis


Abstract

When resting cell suspensions of the anaerobic P. shermanii were brought to an oxygen concentration of 0.64 μmoles/ml, acid formation was completely inhibited. The cells started to respire on the propionic acid previously accumulated during anaerobiosis. Glucose consumption was concomitantly decreased to about 60 percent of the rate obtained during anaerobiosis. As the viability of the cells was not affected by the transition to aerobic conditions, the changes observed upon aeration were ascribed to the regulatory properties of the Pasteur reaction. Damage inflicted by oxygen was encountered in the rapid inactivation of propionate respiration. This damage outlived the time of oxygenation, and was manifested during the subsequent anaerobiosis in the decreased activity to form propionate. This indicates that oxygen may inactivate one (or more) enzyme(s) involved in the metabolism of propionate. The viability of cells in buffer, and glucose‐containing buffer, was found to be only insignificantly decreased by oxygen in the range from 0 to 500 μmoles of oxygen per g of wet cells.