High PHA production and storage using palm oil mill effluent (POME) was investigated using a laboratory batch Bio-PORec (R) system under aerobic-feeding conditions. Results showed that maximum PHA was obtained at a specific rate (q(p)) of 0.343 C-mol/C-mol h when air was supplied at 20 ml/min. The PHA yield was found to be 0.80 C-mol/C-mol acetic acid (HAc) at microaerophilic condition and the mass balance calculation showed that PHA production increased up to 15.68 +/- 2.15 C-mmol/cycle. The experiments showed that short feeding rate, limited requirements for electron acceptors (e.g. O-2, NO3) and nutrients (N and P) showed lower tendency of glycogen accumulation and contributed more to PHA productivity. (C) 2012 Elsevier Ltd. All rights reserved.