The utilisation of CO(2) in the dissimilation of glycerol by the propionic acid bacteria.

This paper by Wood and Werkman is truly outstanding. First, it is a classical example of determination of the path of a fermentation by careful quantitative analyses of substrates consumed and products formed. Second and most importantly, the results led to the discovery of CO2 fixation by heterotrophic bacteria. The dogma at the time the work was done and as expressed in textbooks held that only specially adapted chemosynthetic and photosynthetic autotrophic microorganisms, and of course plants, could fix CO2. The analyses by Wood and Werkman indicated that succinate was the product of the fixation. This was confirmed by Wood et al. in 1941 with the use of CO2 and mass spectroscopy. The discovery by Wood was extended by him and by others to involve livers from higher animals, and it is now clear that several types of CO2 fixation reactions occur in most if not all cells. The discovery of heterotrophic CO2 fixation is important, because this process is needed for converting pyruvate to oxaloacetate (a reaction named the Wood-Werkman reaction long before the actual enzyme catalyzing the reaction was characterized) to connect glycolysis with the citric acid cycle, for synthesis of malonyl-CoA needed for synthesis of lipids, for the function of the urea cycle, and for numerous other metabolic processes including the synthesis of nucleotides, DNA, and RNA. How the discoverers of heterotrophic CO2 fixation avoided getting a Nobel Prize is difficult to understand. LARS G. LJUNGDAHL