Figure 1: Schematic representation of the 3-hydroxyacid pathway.

Genes in blue were overexpressed, including one of the activation enzymes (encoded by pct, prpE or ptb-buk), one thiolase enzyme (encoded by bktB), one of the two 3-hydroxybutyryl-CoA reductases (encoded by phaB or hbd), and one thioesterase enzyme (encoded by tesB). The carbon sources used in the system were glucose and one precursor substrate depicted enclosed by a rectangular box. The precursor substrates and their corresponding 3-hydroxyalkonoic acid products are colour coded accordingly.