Fermentation pathway and redistribution of 14C in specifically labelled glucose in Cellulomonas

The distribution of ¹⁴C among and within the fermentation products formed by the fermentation of specifically labelled glucose by cellulomonades was in the main found to be compatible with a glucose breakdown via the Embden-Meyerhof-Parnas pathway. However, ¹⁴C-acetic acid labelled in both carbon atoms was formed when 3-¹⁴C- or 3.4-¹⁴C-glucose was fermented. In addition, lactic acid formed from 1-¹⁴C-, 2-¹⁴C- or 6-¹⁴C-glucose contained significant amounts of label in the carboxyl group. This non-glycolytic 14C-distribution is not caused by an additional, hitherto unknown catabolic pathway. It is, however, the result of a very effective symmetric interchange and an asymmetric redistribution of carbon atoms within the hexose molecule caused by the reversible action of aldolase, transaldolase and transketolase on sugar phosphates before their final breakdown. Up to the present, such randomization processes have been observed only in algae, plants and animal tissues.