Under photoautotrophic growth conditions, N. muscorum Agardh accumulated the homopolymer of poly-β-
hydroxybutyrate (PHB), whereas synthesis of P(3HB-co-3HV) co-polymer was detected under propionate- and valerate supplemented
conditions. Exogenous carbons such as acetate, fructose and glucose supplementation with propionate/valerate
was found highly stimulatory for the co-polymer accumulation; the content reached 58–60% of dry cell weight (dcw) under
P-/N-deficiencies with 0.4% acetate + 0.4% valerate supplementation, the highest value reported so far for P(3HB-co-3HV)
co-polymer-producing cyanobacterial species. The material properties of the films were studied by mechanical tests, surface
analysis and differential scanning calorimetry (DSC).