Seed culture is to be prepared in a 1 L Erlenmeyer flask containing 200 mL media. Batch cultivation is to be carried out at 30ºC in a 7 L LF-1523 Bioengineering (Bioengineering AG, Switzerland) bioreactor containing 4 L of media. The reactor has to be sterilized in-situ at 121ºC for 20 min, cooled and then inoculated with 5% inoculum (v/v). Culture pH is to be maintained at 7.0 by automatic addition of acid or base by pH–mV controller M 7832 N. Dissolved oxygen concentration is to be maintained at 30% saturation value by manually adjusting the speed of the agitator and/or airflow rate. Samples are to be withdrawn at regular intervals and analysed for biomass, PHB and residual nutrients.