Enhanced Bioethanol Production From Metabolic Engineering Of Enterobacter Aerogenes Atcc 29007
This study investigates the enhancement of bioethanol production using a genetic engineering approach. The bioethanol-producing strain, E. aerogenes ATCC 29007, was engineered by deleting the D-lactate dehydrogenase (ldhA) gene to block the production of lactic acid. The colony PCR was used to confirm the deleted gene. Glycerol, a useful byproduct in the biodiesel industry, was employed to convert into bioethanol, using engineered E. aerogenes SUMI014. Under optimal conditions of fermentation (34 °C, pH 7.5, 78 h), bioethanol production by the mutant strain was 34.54 g/L, 1.5 times greater than that produced by its wild type (13. 09 g/L). Subsequent overexpression of alcohol dehydrogenase (adhE) gene in the mutant strain; increased the production of bioethanol up to 38.32 g/L. By the combination of gene deletion and overexpression, the bioethanol yield was 0.48 g/g when employing 80 g/L glycerol. Hence, a significant enhancement in ethanol production was observed.
Keywords- Alcohol dehydrogenase, D-lactate dehydrogenase, Enterobacter aerogenes ATCC29007, Enterobacter aerogenes SUMI014, Enterobacter aerogenes SUMI2008