Metabolic flux modeling enables optimized production of organic acids for bioleaching

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diagram shows predictive metabolic modeling supported by laboratory testing can be used to develop improved production of organic acid lixiviants for economical bioleaching processes.
Predictive metabolic modeling supported by laboratory testing can be used to develop improved production of organic acid lixiviants for economical bioleaching processes.

CMI researchers at Idaho National Laboratory conducted the research for this highlight

Innovation 
Developed a metabolic model for sugar conversion to chelating organic acids in Gluconobacter oxydans; the acids can be used for bioleaching of metals from solid wastes.

Achievement  
Modeling predicted increasing the C:N ratio in the feed to >10, gluconic acid production would increase substantially. This predictions was validated. When the C:N ratio was increased from 8 to 17, the gluconic acid production increased from 23 to 147 mM. Previous work has shown that higher gluconic acid concentrations are correlated with higher REE recovery yields from FCC catalyst.

Significance and Impact
Model predictions for bioconversion of glucose to organic acids can aid optimization of bioleaching yields, economics and environmental outcomes.

Hub Target Addressed 
Advancing environmentally friendly and efficient recovery of critical materials from end‐of‐life products or wastes.

Comparison of predicted and measured gluconic acid and 2-ketogluconic acid production as a function of the C:N ratio in the feed provided to G. oxydans. 
Comparison of predicted and measured gluconic acid and 2-ketogluconic acid production as a function of the C:N ratio in the feed provided to G. oxydans.