The bacterial strain isolated from soil was identified as Cupriavidus necator IBP/SFU-1 and investigated as a PHA producer. The strain was found to be able to grow and synthesize PHAs under autotrophic conditions; it also showed a broad organotrophic potential towards different carbon sources: sugars, glycerol, fatty acids, and plant oils. The highest cell concentrations (7-8 g/L) and PHA contents were produced from oleic acid (78%) and fructose, glucose, and palm oil (over 80%). The type of the carbon source influenced PHA chemical composition and properties: when grown on oleic acid, the strain synthesized the P(3HB-co-3HV) copolymer; on plant oils – the P (3HB-co-3HV-co-3HHx) terpolymer, and on the other substrates – the P(3HB) homopolymer. The type of the carbon source influenced molecular-weight properties of PHAs: P(3HB) synthesized under autotrophic growth conditions, from CO₂, had the highest number-average (290±15 kDa) and weight-average (850±25 kDa) molecular weights and the lowest polydispersity (2.9±0.2); polymers synthesized from organic carbon sources showed increased polydispersity and reduced molecular weight. Carbon source was not found to affect the degree of crystallinity and thermal properties of the PHAs. The type of the carbon source determined not only PHA composition and molecular weight but also surface microstructure and porosity of polymer films.