Use of enzymes in extraction of polyhydroxyalkanoates produced by Cupriavidus necator

Poly(3-hydroxybutyrate) (P(3HB)) and its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV), are biodegradable thermoplastic polymers. They are members of the polyhydroxyalkanoate (PHA) family, synthesized and accumulated as a carbon and energy reserve by a variety of microorganisms. The aim of this study was to evaluate the use of the proteases Corolase® L10, Alcalase® 2.4L, Corolase® 7089 and Protemax® FC and glycosidases Celumax® BC, Rohament® CL and Rohalase® Barley for the recovery of P(3HB) and P(3HB-co-3HV) synthesized by Cupriavidus necator. The enzyme Celumax® BC provided better lysis of the bacterial cell membrane and the results for the optimization of the operating conditions showed that this enzyme is most stable in acetate buffer at pH 4.0, bath at 60°C, hydrolysis time of 1 h and concentration of 0.02% (w/w). The optimization of the operating conditions showed that the enzyme Celumax® BC provided better lysis of the bacterial cell in acetate buffer at pH 4.0, bath at 60°C, hydrolysis time of 1 h and concentration of 0.02% (w/w). These conditions resulted in lysis of the membrane of the bacteria with a recovery of 93.2% P(3HB-co-3HV) with 94% purity. The results showed that the use of enzymes for the polymer extraction is an efficient process that assists in the cell disruption of Cupriavidus necator.