Fig. 3

Acetate metabolism and mutant construction in Synechocystis. a Schematic representation of acetate producing (blue) and consuming (orange) pathways, revealed by the genome-scale model (GSM) [30]. Acetate is also produced as an anabolic by-product and secreted (by an as of yet unknown mechanism). Genes (red and italic) related to acetate consuming pathways were deleted in this study. Pink arrowheads indicate the direction of the AckA predicted in the GSM, but found to be infeasible under the experimental conditions tested. b PCR confirmation of the strains constructed for markerless deletion of acs and ackA. With the primers on each side of the upstream and downstream homologous region (~ 1 kb each), a markerless construct gave a PCR product ~ 2 kb, while the wild-type band was about 4 and 3.2 kb for acs and ackA, respectively