Use of enzymes in extraction of polyhydroxyalkanoates produced by Cupriavidus necator

Abstract

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.

Effective recovery of poly‐β‐hydroxybutyrate (PHB) biopolymer from Cupriavidus necator using a novel and environmentally friendly solvent system

“…Certain enzyme‐assisted PHB extraction process was reported to have high recovery yield (93.2%) and purity (94%) of PHB . However, the enzymes were merely used to lyse the cell wall, and the PHB was still extracted by using chloroform which is a carcinogen.…”

Microbial Polyhydroxyalkanoates and Nonnatural Polyesters

“…Various enzymes such as cellulases, lysozymes, and proteases such as trypsin and papain have been evaluated for this purpose. [267,268] Extraction of PHAs by this method resulted in high purity and yield of PHAs with good polymer quality. However, the high costs of enzymes and relatively complex process including heat treatment make this process economically unattractive.…”

Biotic and Abiotic Synthesis of Renewable Aliphatic Polyesters from Short Building Blocks Obtained from Biotechnology

“…[295] This method includes the use of surfactants, [431] surfactants with alkali [432] or chelates, [433] alkali alone [434] or in combination with acids, [435] enzymes, [436] andc hemicals. [295] This method includes the use of surfactants, [431] surfactants with alkali [432] or chelates, [433] alkali alone [434] or in combination with acids, [435] enzymes, [436] andc hemicals.…”

“…Many alternative processes have been developedi nw hich, for example, the non-PHA cell mass is solubilized (digestion treatment). [295] This method includes the use of surfactants, [431] surfactants with alkali [432] or chelates, [433] alkali alone [434] or in combination with acids, [435] enzymes, [436] andc hemicals. [437] In addition to chemical disruption, mechanical (high-pressure homogenization, bead milling) or physical( e.g.,f reezing, osmotic shock, ultrasonication) treatments can be employed, even if they are expensive and not easily industrially scalable.…”