Acetate accumulation through alternative metabolic pathways in ackA (-) pta (-) poxB (-) triple mutant in E. coli B (BL21).

Je-Nie Phue, Sang Jun Lee, Jeanne B Kaufman, Alejandro Negrete, Joseph Shiloach

Index: Biotechnol. Lett. 32(12) , 1897-903, (2010)

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Abstract

Individual deletions of acs and aceA genes in E. coli B (BL21) showed little difference in the metabolite accumulation patterns but deletion of the ackA gene alone or together with pta showed acetic acid gradually accumulated to 3.1 and 1.7 g/l, respectively, with a minimal extended lag in bacterial growth and a higher pyruvate formation. Single poxB deletion in E. coli B (BL21) or additional poxB deletion in the ackA-pta mutants did not change the acetate accumulation pattern. When the acetate production genes (ackA-pta-poxB) were deleted in E. coli B (BL21) acetate still accumulated. This may be an indication that perhaps acetate is not only a by-product of carbon metabolism; it is possible that acetate plays also a role in other cellular metabolite pathways. It is likely that there are alternative acetate production pathways.