Strategies of poly(3-hydroxybutyrate) synthesis by Haloarcula sp. IRU1 utilizing glucose as carbon source: Optimization of culture conditions by Taguchi methodology

We investigated optimization of poly(3-hydroxybutyrate) (PHB) production by Haloarcula sp. IRU1 in a batch culture system. Various batch experiments were carried out at different carbon source concentrations [glucose, at 1–8% (w/v)], phosphorus source concentrations [K2HPO4, KH2PO4, Na3PO4 and Na2HPO4 at 0.001–0.016% (w/v)], nitrogen source concentrations [NH4Cl, yeast extract, peptone and tryptone at 0.1–0.8% (w/v)] and temperatures [37–55 °C]. By these experiments, optimum production conditions were determined using the Taguchi method. The results showed the highest PHB production by Haloarcula sp. IRU1 (63.0% of cell dry weight) in the presence of 2 g/l glucose, 0.2 g/l NH4Cl, 0.004 g/l KH2PO4 and temperature (42 °C). In overall, the results of this study showed that Haloarcula sp. IRU1 has a high potential for synthesis of PHB from glucose.