Protein Engineering of Enzymes Involved in Bioplastic Metabolism

Abstract

Meanwhile, poly(ethylene) (PE) and poly(propylene) (PP) are chemically synthesized from their monomers derived from biological sources, but they are not biodegradable. Poly(hydroxyalkanoate)s (PHAs) and poly(lactide) (PLA) show an excellent biodegradability, and are produced from renewable resources via biological and chemical processes, respectively. Thus, the bio-based bioplastics having biodegradability, such as PHAs and PLA, are the most favorable bioplastics to avoid the above-mentioned problems associated with the use of petrochemical-based synthetic plastics. T. Hiraishi and S. Taguchi Figure 1. Bioplastics comprised of biodegradable and bio-based plastics.

Polyhydroxyalkanoates Production from Ralstonia Pickettii Bacteria: Structural and Mechanical Studies

“…The biomass concentration of PHA-producing cells varies greatly due to various factors which affect the fermentation process. However, a different result was found in Azotobacter beijerinckii WDN-01 of 4.7 g/L and Cuprividus necator of 0.15 g/L [25,26]. The differences in the numbers of harvested biomass were considerably influenced by several factors, such as the type of isolates either original or recombinant, the source of carbon or nitrogen, fermented pH, C/N ratio, and fermentation method including batch or fed-batch.…”

“…Nucleophilicity from the hydroxyl group of Ser39 was enhanced by the system of hydrogen bonds of His155-Asp121. The genetic analysis also discovered certain catalytic triads comprising S139, D214, and H273 on the enzyme of PhaZRpiT1 (PHA depolymerase of Ralstonia pickettii), which degraded PHA [26]. The excess amount of PHA depolymerase indicates that the optimum time of PHA extraction from R. pickettii is in the middle of the stationary phase.…”

Anaerobic Biodegradability of Commercial Bioplastic Products: Systematic Bibliographic Analysis and Critical Assessment of the Latest Advances

“…Molecular biology techniques could be used as a tool to this aim. In the past years, many attempts have been made to improve bioplastic production processes through the use of modified enzymes by protein engineering [ 104 ], while investigation on applications to enhance bioplastic degradation is still in its infancy. However, enzymatic degradation of bioplastics could represent a viable option if correctly assessed and standardized [ 105 ].…”

Biodegradable Polymers: Recent Developments and New Perspectives

“…More than 30 PHA depolymerase genes, with experimentally verified activity, have been identified, and the PHA depolymerase Engineering Database has been established based on their sequence similarity [86]. Among the PHA depolymerases, multi-domain PHB depolymerases have been extensively studied [87][88][89]. Multi-domain PHB depolymerases generally consist of a catalytic domain (CD) at the N-terminus, a substrate-binding domain (SBD) at the C-terminus, and a linker region connecting the two domains [87].…”