1959 Volume 12 Issue 4 Pages 160-168
In is an already known fact that α-ketoglutarate is a member of the tricarboxylic acid cycle and it plays a very important role in the carbon metabolism of microorganisms. Lockwood and Stodola1) (1946) found that Pseudomonas fluorescens NRRL No. B-6 produced α-ketoglutarate as major product from glucose under aerobic conditions. Thereafter, several in vestigators have al so reported the production of α-ketoglutarate with various kinds of microorganisms; i.e., in addition to genus Pseudomonas2,3,4,5), genera Escherichia6), Aerobacler6) and Proteus6), Serratia marcescens5,8,9), Bacillus natto7), B. megatherium7), Bact. succinicum7),Gluconoacetobacter cerius10) and Bact. No. 84 C10), Bact. ketoglutarium11), genus Streptomyces12), Mycobacterium butylicum13), Corynebacterium creatinovorans14), Vibrio15), Achromobacter16),Aspergillus niger17), Aspergillus oryzae18,19), Rhizopus18), and Penicillium chrysogenum20,21).
In order to clarify the mechanism of α-ketoglutarate formation by the bacteria, many studies have been carried out. Lockwood et al. 1) reported that glucose oxidation by Pseudomonas fluorescens proceeded to α-ketoglutarate by way of the hypothetical hexose monophosphate shunt reaction sequence. Alternatively, instead of proceeding according to the contemporary hypothesis, it was suggested by Koepsell et al.2,3) that 2-ketogluconate dissimilation might yield a 3-carbon or a 2-carbon fragment in addition to pyruvate, and α-ketoglutarate might arise by condensation of pyruvate with these fragments . Recently, another idea has been shown by Weimberg et al.22) who have investigated the oxidation of L-arabinose by Pseudomonas saccharophila. They found that this pentose could be converted to α-petoglutarate by a series of reactions which did not involve the tricarboxylic acid cycle; i.e., L-arabinose→L-arabono-γ-lactone→L-arabonate→α-ketoglutarate. And other investigators15,23,24,25) reported that α-ketoglutarate would be formed through the tricarboxylic acid cycle. While, Katagiri, Tochikura and Imai6) found that coli-aerogenes bacteria accumulated a large amount of α-ketoglutarate under aerobic conditions such as shaking culture during investigations on the metabolism of glucose. Additional experiments26,27,28,29,30), on the oxidative fermentations of di-and tri-carboxylic acids of the tricarboxylic acid cycle, led to a conclusion that major production of α-ketoglutarate from glucose did not arise by way of the tricarboxylic acid cycle, but occurred by a new “pyrurate-acetate reaction”; i.e., pyrurate+acetyl -CoA→α-ketoglutarate.
Thereupon, investigators often use the inhibitors for the study of biochemical reactions. The potent, specific, and permeant inhibitors of the carbon metabolism would be useful tools for the observation of the relations of the carbon metabolism to cell function. There are numerous reports that the antitubercular substance is available as relatively specific inhibitor of the terminal respiration process. Umbreit and his associates31,32,33) studied the effect of streptomycin on terminal oxidation in Escherichia coli and... Please see PDF for more.
