Abstrakt

Production of poly(hydroxyalkanoates) by Halomonas pantelleriensis grown on glycerol from bio-diesel

Filomena M.Vella, Ida Romano, Barbara Immirzi, Agata Gambacorta

Glycerol from bio-diesel production was used in the production of poly(hydrohyalkanoates) feeding cultures of the haloalkaliphilic bacterium Halomonas pantelleriensis. The micro-organism grew well and biosynthesized poly[3-hydroxybutyrate (P3HB)]. Themaximumyields, 10-11% of cell dryweight, was obtained after 72 hwith 0.5%industrial glycerol and nitrogen source 0.1 g l-1 at 35°C and after 10 days with glycerol 1.0%. The growth with 0.1%glycerol and 0.4%valerate gave a mixed polymer P(HBHV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in a ratio 90:10. For quantification of glycerol and of valerate during theH.pantelleriensis growth, and of PHAs, 1H -NMRwas used.MS spectroscopy, FTIR and 1H, 13C-NMR were used to chemically characterize the PHAs. The thermal characteristics of polymers were obtained using a differential scanning calorimeter and the average viscositymolecular weight was assessed through specific viscosity measurements.