Fig. 4

Production of PHB by H. boliviensis using an air-lift reactor with an air inflow that varied between 0.5 and 0.9 L/min and molasses and glucose used as carbon sources. The maximum airflow rate was reached at 30 h, pH was maintained at 7.5 and water at 35 °C was circulated by the jacket of the reactor. A mixture of molasses (15 g/L) and glucose (5 g/L) was used as carbon source in the medium. A solution of molasses (500 g/L) was fed to the reactor after 14 h of cultivation. Experiments were performed in duplicate. CDW, cell dry weight and RCM, residual cell mass