Biosynthesis of poly(4-hydroxybutyrate) in recombinant Escherichia coli grown on glycerol is stimulated by propionic acid.
One of the most promising polyhydroxyalkanoates (PHAs) for medical applications is poly(4-hydroxybutyrate) (P4HB) due to its biodegradability, biocompatibility and mechanical properties. Currently, the major hurdle for expanding P4HB applications is the production and recovery cost. In this study, we investigated the stimulating factors for P4HB biosynthesis with the ultimate goal of reducing production cost. We found that addition of propionic acid to the culture medium stimulates the P4HB accumulation in recombinant Escherichia coli JM109 grown on glycerol. This stimulating effect was significantly weakened by addition of exogenous methionine, whereas it was not influenced by addition of cysteine. These results suggest that propionic acid enhances P4HB synthesis by reducing the intracellular methionine pool. Utilizing these findings for P4HB production in batch cultures on glycerol, the volumetric yield of P4HB could be improved 4 fold from 0.9g/L to 3.7g/L by adding 2g/L propionic acid into the medium.
Laboratory for Biomaterials, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
Michael M
MM
Kämpf
Laboratory for Biomaterials, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
Linda
L
Thöny-Meyer
Laboratory for Biomaterials, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland. Electronic address: qun.ren@empa.ch.
Qun
Q
Ren
D019149:Bioreactors; D003470:Culture Media; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism / Q000494:pharmacology; D011091:Polyesters / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism* / Q000494:pharmacology
D003470:Culture Media; D011091:Polyesters; D011422:Propionates; C107955:poly(4-hydroxybutanoate); D008715:Methionine; D005947:Glucose; C029658:propionic acid; D005990:Glycerol
Batch culture; Glycerol; P4HB; Propionic acid