A process for simultaneously achieving phenol biodegradation and polyhydroxybutyrate accumulation using Cupriavidus taiwanesis 187

Cupriavidus taiwanensis 187 is reportedly efficient in achieving the degradation of phenol and accumulation of polyhydroxybutyrate (PHB). This study attempted to optimize the cultivation conditions and fermentation strategies for phenol degradation and PHA accumulation by C. taiwanensis 187. After the cultivation conditions were optimized, the conditions required for achieving phenol degradation (100%) and PHB accumulation (51 mg/L) by C. taiwanensis 187 were identified as 30 °C and 200 rpm, when the cultivation time was around 7 h. The accumulation of PHB was further increased from 72 to 213 mg/L by feeding phenol in three rounds into the fermenter along with the exhaustion of dissolved oxygen, which could totally degrade the phenol at around 1500 mg/L. Production of PHB by C. taiwanensis 187 was confirmed by GC, 1H-NMR, and 13C-NMR analyses. Each analytical result proved that C. taiwanensis 187 was able to use phenol as the sole carbon source for producing PHB. Finally, these results revealed that the phenol degraded by C. taiwanensis 187 mainly contributed to cell growth rather than PHB accumulation. These results indicated that the strain C. taiwanensis 187 could be used to degrade phenol to obtain usable biological polyesters.