Genome-Wide Metabolic Reconstruction of the Synthesis of Polyhydroxyalkanoates from Sugars and Fatty Acids by Sensu Lato Species.

sensu lato (s.l.) species have a versatile metabolism. The aims of this review are the genomic reconstruction of the metabolic pathways involved in the synthesis of polyhydroxyalkanoates (PHAs) by s.l. genera, and the characterization of the PHA synthases and the genes organization. The reports of the PHA synthesis from different substrates by s.l. strains were reviewed. Genome-guided metabolic reconstruction involving the conversion of sugars and fatty acids into PHAs by 37 s.l. species was performed. Sugars are metabolized via the Entner-Doudoroff (ED), pentose-phosphate (PP), and lower Embden-Meyerhoff-Parnas (EMP) pathways, which produce reducing power through NAD(P)H synthesis and PHA precursors. Fatty acid substrates are metabolized via -oxidation and de novo synthesis of fatty acids into PHAs. The analysis of 194 s.l. genomes revealed that all strains have the , and genes for PHA synthesis, wherein the gene is generally present in ≥2 copies. PHA synthases were classified into four phylogenetic groups belonging to class I II and III PHA synthases and one outlier group. The reconstruction of PHAs synthesis revealed a high level of gene redundancy probably reflecting complex regulatory layers that provide fine tuning according to diverse substrates and physiological conditions.