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The activities of 15 glycolytic and related enzymes were determined in clostridia. All contained 1-phosphofructokinase; three of them lacked 6-phosphofructokinase and mannitol 1-phosphate dehydrogenase. Glucose 6-phosphate dehydrogenase was found in six clostridia, thus demonstrating the presence of hexose monophosphate shunt. Only parts of the citric acid cycle were found to be present in most clostridia with an indication of the full cycle in Clostridium septicum. The intermediary enzyme activities were used to differentiate between the different clostridia. Although clostridia are well-known for their production of wound and food toxins, they also have other interesting metabolic features. A review by Barker (1) indicated that a number of clostridia can ferment amino acids, purines, pyrimidines, allantoin, and nicotinic acid. Clostridium pasteurianum has been shown to fix atmospheric nitrogen (3, 6), C. sporogenes obtains its energy from the oxidation-reduction reaction between pairs of amino acids (20, 21), and still others were reported to ferment carbohydrates (3). The association of clostridia with anaerobic digestion has been indicated by several investigators. Bonde claimed that C. perfringens was a better indicator organism for sewage pollution of water than coliform bacteria (2). Johannsen found C. botulinium type E ubiquitous in the Baltic sea (12). Burbank et al. isolated anaerobic and facultative bacteria from the digestion process and identified, among others, C. carnofoetidum (4). Siebert and Toerien isolated C. bifermentans, C. tale, and C. perenne from anaerobic sludge (M. L. Siebert and D. F. Toerien, Water Res., in press),

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KISTNER, A., and J. P. KOTZB. 1973. Enzymes of intermediary metabolism of Butyriuibrio fibrisoluens and Ruminococcus albus grown under glucose limitation. Can. J. Microbiol. 19: 1119-1127. A survey was made of enzyme activities in cell-free extracts prepared from one strain each of B~rtyriuibriofibrisoluerrs and Ruminococcus albus, two anaerobic cellulolytic rumen bacteria, which had been grown in continuous culture on a defined medium under glucose limitation. In both organisms the enzymes of the glycolytic sequence up to the cleavage of hexosediphosphate were demonstrated, except that 6-phosphofructokinase activity in B.fibrisoluer~s was barely measurable. Instead, l-phosphofructokinase was found in this organism. The role of this enzyme in glucose-grown cells is uncertain. Phosphopyruvate hydratase and pyruvate kinase could not be detected in R. albus extracts and their activities were extremely low in B.fibrisolvens, thus posing a problem as to pyruvate production in these organisms. At least part of the tricarboxylic acid cycle appeared to be functional in both organisms.Since several or the enzymes of this cycle in B. fibrisoluer~s were NADP-dependent, rather than NAD-dependent, and other workers have shown that fumarate reductase activity exceeds succinate dehydrogenase activity by more than 3 :1, it is suggested that the tricarboxylic acid cycle may operate as a reductive cycle in this organism. Both organisms possessed fairly high activities of glutamate dehydrogenase and aspartate aminotransferase. The information obtained is inadequate to map out the pathways leading to the main end products of glucose fermentation.KISMER, A., et J. P. KorzB. 1973. Enzymes of intermediary metabolism of Butyriuibrio fibrisoluer~s and Ruminococc~s albus grown under glucose limitation. Can. J. Microbiol. 19: 11 19-1 127. Une etude a Ct C faite des activites enzymatiques d'extraits acellulaires prepares a partir d'une lignCe de chacune de deux bactkries cellulotiques anairobiques du rumen, Butyrivibriofibrisoluens et R~~mir~ococc~rs albus, lesquelles se sont dCveloppCes en culture continue dans un milieu defini sous des limitations de glucose. Chez les deux organismes, les enzymes de la sequence glycolytique jusqu'au clivage de l'hexosediphosphate furent dCmontrkes, except6 celui de la 6-phosphofructokinase chez B. fibrisoluens qui est rarement mesurable; cependant, la 1-phosphofructokinase est trouvte chez cet organisme. Le r81e de cette enzyme cllez des cellules dCveloppCes sur glucose est incertain. L'hydratase phosphopyruvate et ]a kinase pyruvate ne peuvent pas Ctre dCtectCes de R. albus et leurs activitks sont extrhement faibles chez B.fibrisolvens, posant alors un problkme en regard de la protection du pyruvate chez ces organisnles. AU moins une partie du cycle de I'acide tricarboxylique apparait &re fonctionnelle chez ces deux organismes.Coinme plusieurs des enzymes de ce cycle chez B. fibrisoluerrs sont dependants du NADP, au lieu du NAD, et que d'autres chercheurs ont montrk que I'activite de la reductase du funl...