ISSN:
1432-072X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary 1. The efficiency of oxidative phosphorylation was estimated in intact “resting” cells of Proteus mirabilis, Escherichia coli B, Aerobacter aerogenes, Pseudomonas aeruginosa and Azotobacter vinelandii, measuring the change of ATP, ADP, AMP and NAD+ occurring on addition of limiting amounts of O2 to anaerobic cells of these bacteria. Also, in some cases O2-uptake was measured directly with a vibrating Pt-electrode. 2. Intact cells of P. mirabilis exhibited oxidative phosphorylation with a P/O-ratio of about 0.6–1.0. For A. aerogenes, P. aeruginosa and A. vinelandii a P/O-ratio of 0.30; 0.50 and 1.0 was found, respectively. 3. The reduction of NO3 - by anaerobic cells of P. mirabilis was accompanied by phosphorylation with a P/2e-(NO3 -)-ratio of about 0.37. 4. Changes in NAD+ were not representative of the amount of O2 consumed. So, methods in which the oxidation of NADH alone is taken as a measure for oxidative phosphorylation in bacteria do not give reliable P/2e--ratios. 5. It is concluded that P/O-ratios in intact “resting” bacterial cells are not as high as those for intact mitochondria from higher organisms and are also lower than P/O-ratios found for growing cells of bacteria.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00408900
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