Polyhydroxyalkanoates production by engineered Cupriavidus necator from waste material containing lactose.
Cupriavidus necator DSM 545 is a well-known polyhydroxyalkanoates (PHAs) producer, but unable to grow on lactose. The aim of this study was to construct a recombinant strain of C. necator that can use lactose-containing waste material such as cheese whey, to produce PHAs. One of the intracellular PHA depolymerases (phaZ1) of C. necator was chosen to insert the lacZ, lacI and lacO genes of Escherichia coli. This would have the effect to allow polymer production on lactose and, at the same time, to remove part of the PHA intracellular degradation system. Disruption of phaZ1 was achieved by gene replacement after isolating a fragment of this gene and interrupting it with a cartridge containing the lac genes and a synthetic promoter. Growth and polymer production studies of the genetically modified (GM) strain mRePT in lactose, whey permeate and hydrolyzed whey permeate as carbon sources, were performed. Lower PHA degradation and higher yields were obtained compared to the wild-type strain. Inactivation of the putative depolymerase gene phaZ3 on mRePT recombinant strain was also reported.
Dipartimento di Biotecnologie Agrarie, Università di Padova, Viale dell'Università 16, 35020 Legnaro Padova, Italy.
Silvana
S
Povolo
Paolo
P
Toffano
Marina
M
Basaglia
Sergio
S
Casella
D003470:Culture Media; D020118:Cupriavidus necator / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D007785:Lactose / Q000378:metabolism*; D008894:Milk Proteins / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D000067816:Whey Proteins
D003470:Culture Media; D004269:DNA, Bacterial; D008894:Milk Proteins; D054813:Polyhydroxyalkanoates; D000067816:Whey Proteins; D007785:Lactose