Production of medium-chain-length polyhydroxyalkanoates by high-cell-density cultivation of Pseudomonas putida under phosphorus limitation

High‐cell‐density fed‐batch cultures of Pseudomonas putida were carried out for the production of medium‐chain‐length polyhydroxyalkanoates (PHAs) using oleic acid as a carbon source. By employing an optimal feeding strategy without the limitation of any nutrient, a high cell concentration of 173 g/L was achieved, but the PHA concentration and PHA content were only 32.3 g/L and 18.7 wt%, respectively. To increase the PHA concentration and content, phosphorus limitation was applied during fed‐bath culture by reducing the initial KH2PO4 concentration. When the initial KH2PO4 concentration was reduced to 4 g/L, cell concentration, PHA concentration, and PHA content obtained in 38 h were 141 g/L, 72.6 g/L, and 51.4 wt%, respectively, resulting in a high productivity of 1.91 g PHA/L per hour. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 466–470, 2000.