The relationship between the energetic efficiency in different micro-organisms and the rate and type of metabolite overproduced

Data regarding the degree of energy conservation as determined by the YO₂ᵐᵃˣ and the highest rates of metabolite production reported for various micro-organisms have been collated and analysed. The results have indicated that the highest rates of metabolite production occur in micro-organisms possessing low efficiencies of energy conservation. Moreover, in the case of exopolysaccharide production the oxidation state of the polymer is inversely related to the YO₂ᵐᵃˣ value of the producing organism. In general, the rate of ATP turnover associated with exopolysaccharide production or the potential rate associated with over-production of other metabolites is inversely related to the YO₂ᵐᵃˣ value of the producing organism. Analysis of current production rates for a range of metabolites suggests that there is scope for major improvements of existing processes by careful selection of appropriate micro-organisms.