High production of poly-β-hydroxybutyrate (PHB) by an Azotobacter vinelandii mutant altered in PHB regulation using a fed-batch fermentation process

摘要: Abstract A mixed fermentation strategy based on exponentially fed-batch cultures (EFBC) and nutrient pulses with sucrose yeast extract was developed to achieve a high concentration of PHB by Azotobacter vinelandii OPNA, which carries mutation the regulatory systems PTSNtr RsmA-RsmZ/Y, that negatively regulate synthesis PHB. Culture OPNA strain in shake flaks containing PY-sucrose medium significantly improved growth production respect results obtained from parental (OP). When cultured batch keeping constant DOT at 4%, maximal rate (0.16 h−1) yield (0.30 gPHB gSuc−1) were reached. Later, EFBC, increased three fold biomass 2.2 relation values cultures. Finally, using exponential feeding coupled (with extract) 7-fold reach 27.3 ± 3.2 g L−1 60 h fermentation. Overall, use mutant A. impaired systems, combination could be feasible optimize industrial level.