The unified metabolism of Gluconacetobacter entanii in continuous and batch processes

The capabilities of Gluconacetobacter spp. to grow on polyol carbon sources through partial oxidation and to synthesize carbohydrate polymers have been noted early in microbiology, yet this genus is now the object of renewed research attention. We address the complex physiology of a species recently classified into this genus, Gluconacetobacter entanii, in transient and steady state experiments. The interdependence between the two main catabolic routes and their links to central metabolism and anabolic routes are supported by our experiments. The disperse accounts of the various catabolic, central metabolism and anabolic pathways are assembled into an integral metabolic structure. A lumped bioreaction scheme is proposed and the rate of change of key internal metabolite concentrations is obtained through a simple stoichiometric model. This model helps interpret our experimental results and also to analyze the findings of other researchers. This work shows for the first time an account of the abilities of G. entanii to synthesize cellulose and a hydrophilic polymer (possibly acetan). (c) 2007 Elsevier Ltd. All rights reserved.