Send to

Choose Destination
Biotechnol Bioeng. 1994 Oct;44(8):944-51.

Modification of central metabolic pathway in escherichia coli to reduce acetate accumulation by heterologous expression of the bacillus subtilis acetolactate synthase gene.

Author information

Department of Chemical Engineering, Institute of Biosciences and Bioengineering, Rice University, P.O. Box 1892, Houston, TX 77251-1892.


A novel metabolic engineering technique involving the redirection ofcellular carbon fluxes was employed to reduce acetate production in an Escherichia coli culture. Metabolic engineering was achieved by cloning E. coli the gene for the Bacillus subtilis acetolactate synthase (ALS), an enzyme capable of catalyzing the conversion of pyruvate to nonacidic and less harmful species. The heterologous expression of the ALS catabolic enzyme in Escherichia coli drastically modified the cellular glycolytic fluxes. In particular, acetate excretion, which is a common characteristic of E. coli, as well as a physiological burden, was minimized. The residual acetate level was kept under control and maintained at a level that was below the toxic threshold. The expression of the biologically active ALS enzyme in E. coli did not result in any detectable changes on either cell growth rate or cell yields. The alternative product, acetoin, was shown to be 50 times less harmful than acetate. Similarities in the growth pattern of two different E. coli strains, RR1 and GJT001, under all cultivation conditions suggested that the ability of ALS to reduce acetate accumulation is generic and not strain-specific.


LinkOut - more resources

Full Text Sources

Other Literature Sources


Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center