Polymer Films of Poly-3-hydroxybutyrate Synthesized byCupriavidus necatorfrom Different Carbon Sources

Shishatskaya, Ekaterina; Nemtsev, Ivan; Lukyanenko, Anna; Vasiliev, Alexander; Kiselev, Evgeniy; et al. DOI: https://doi.org/10.1007/s10924-020-01924-3

Films were prepared from 2% solutions of biodegradable poly-3-hydroxybutyrate [P(3HB)] and investigated. The polymer was synthesized by the Cupriavidus necator B-10646 bacterium cultivated using various carbon sources (glucose and glycerol of different degrees of purity, containing 0.3 to 17.93% impurities). Glycerol as the substrate influenced molecular-weight properties and crystallinity of the polymer without affecting its temperature characteristics. The P(3HB) specimens synthesized from glycerol had reduced Mw (300–400 kDa) and degree of crystallinity (50–55%) compared to the specimens synthesized from glucose (860 kDa and 76%, respectively). The low-crystallinity P(3HB) specimens, regardless of the degree of purity of glycerol, produced a beneficial effect on the properties of polymer films, which had a better developed folded surface and increased hydrophilicity. The values of the highest roughness (Ra) of the films synthesized from glycerol were 1.8 to 4.0 times lower and the water angles 1.4–1.6 times smaller compared to the films synthesized from glucose (71.75 nm and 87.4°, respectively). Those films performed better as cell scaffolds: the number of viable NIH fibroblasts was 1.7–1.9 times higher than on polystyrene (control) or films of P(3HB) synthesized from glucose.