A thermophilic peroxidase from an archaea/bacteria with optimum activity at 50-90°C will be used as a starting point for the development of enzymatic biocatalysts.
The objective is to evolve the functionality (allowing conversion of oil compounds) of the enzyme while improving temperature stability (temperature tolerance). In the researcher's previous work, it was shown that the reactions of interest cease to occur in a predominantly organic media such as oil. To activate the enzymes in the oil phase, the enzymes have been modified via molecular genetic techniques called Directed Evolution, resulting in catalysts that are stable and functional in oil. In order to allow conversion using enzymes as catalysts, it is important to know the partitioning of the enzyme between the oil and the aqueous phase. This was investigated using the oxidase enzyme peroxidase. The capability to operate at higher temperatures is useful in thermal recovery and reduces the need for heat exchange equipment in the refining process. Oxidative transformation of the polyaromatics were investigated as a strategy for biorefining heavy crudes, with particular emphasis on lowering molecular weight, decreasing viscosity, and rendering increased availability of sulfur, nitrogen, nickel, and vanadium to further refining technologies.
The enzyme P450 from P. putida is known to have some activity for PAH conversion. Another P450 enzyme-from Sulfolobus solftaricus, a thermophilic organism-is capable of operation at elevated temperatures (80° C.); however, it does not oxidize PAH compounds. In order to produce a thermostable PAH-oxidizing enzyme, a hybrid of these two enzymes was produced.
