Carbon Dioxide Fixation by Actinomyces … A Correction

Abstract

Previously 1 I reported results of experiments on carbon dioxide fixation by strains of Actinomyces and Lactobacillus in which the data indicated a high incorporation of carbon dioxide into the methylene carbons of succinic acid. The data were supported by isolation of beta-alanine formed from succinic acid by the Schmidt degradation done at 40 to 70°C. Recently studies in this laboratory were initiated to determine the mechanism of this reaction in strains of Actinomyces. Although the initial experiments reproduced the previous results, isolation of the methylene carbons of succinic acid as ethylenediamine was preferred since it would eliminate several chromatographic steps and simplify the procedure. Although I had been unsuccessful previously in obtaining ethylenediamine by the procedure of Phares and Long 2 the use of a better grade fuming sulfuric acid and high temperatures permitted adequate formation of ethylenediamine. With some dismay, it was found that the carbon dioxide formed from the ethylenediamine was totally inactive. Subsequently, it was found that failure to adequately trap sulfur dioxide fumes formed by the reaction 3 accounted for the reduced specific activity in the carboxyl carbons. However, the close correlation of the specific activity of the isolated beta-alanine with that predicted is unexplained. The present results clearly show a net fixation of CO₂ are valid. It is, therefore, concluded that anaerobic fixation of CO₂ into succinic acid by Actinomyces primarily occurs via a Wood-Werkman reaction. In air, the oxidation of some intermediate of glucose metabolism results in formation of CO₂ and consequently reduces the specific activity found in the succinic acid.

I regret the error in the analyses and the concomitant circumstances which lead to a misinterpretation of the data. I would like to apologize for any inconvenience the use of such data may have caused.