Fig. 7

A simplified representation of the metabolic effects associated with enhanced acetate influx in Synechocystis sp. PCC 6803 under low-light conditions. Introduction of a heterologous acetate transporter 1 improves the ability of the cell to import supplemented acetate from the medium, which 2 increases the availability of intracellular acetyl-CoA. At the same time, 3 the photosynthetic capacity of the cell is decreased. This is accompanied by 4 the decrease of intracellular glycogen levels, implicating that the available reserves are utilized directly by the cell, instead of storing glucose for future needs. Together this leads to the 5 increased availability of primary precursors for the biosynthesis of, for example, lipids and proteins, as well ATP and reducing equivalents needed to sustain the metabolic reactions. Ultimately, these changes result in 6 enhanced growth of the Synechocystis acetate transporter mutant under low-light conditions in the presence of acetate. In the scheme increase/upregulation is depicted in red and decrease/downregulation in grey