Studies on Carbon Metabolism of Organisms of the Genus Mycobacterium

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Abstract
All spp. of Mycobacterium included in this study possess the ability to obtain C and energy from some carbohydrates, alcohols, and salts of organic acids, when these are present in a synthetic medium and constitute the sole C and energy sources. Utilization of C compounds, as determined by methods here employed, is of sufficiently varied nature to aid in differentiating some of the spp. In media containing salts of organic acids as the C source, the reaction changes associated with growth of these organisms is a primary alkalinity followed by a secondary change back towards neutrality. When media contain carbo-hydrates or alcohols the reaction change is toward pro gressive increase in acidity. There were some cases in which utilization could not be demonstrated by the method used, where the same carbohydrates were shown to be utilized by the same organisms in the carbohydrate broth cultures. In glucose synthetic-media cultures of the spp. of Mycobacterium studied, all the C available in the media was accounted for as CO2 plus the C contained in the organisms, plus that remaining as unutilized carbohydrate. The reaction changed toward increased acidity, accompanying growth of the Mycobacteria in the synthetic medium used. This reaction change can be accounted for completely on a basis of the removal of NH3 from the media. There is no evidence that any cleavage products of the carbohydrates accumulate in the media. It would appear from all evidence at hand that the Mycobacteria utilize carbohydrates completely, no cleavage products accumulating in the media, the carbohydrate being oxidized completely to CO2 and water.