Enhanced enzymatic and ex situ biodegradation of petroleum hydrocarbons in solutions using Alcanivorax borkumensis enzymes in the presence of nitrogen and phosphorus co-doped reduced graphene oxide as a bacterial growth enhancer

Abstract

This manuscript offers a biochemical insight into how the novel strain A. borkumensis can grow effectively on metal-free carbonaceous materials in the presence of hexadecane and BTEX hydrocarbon samples. In the present research, by combination of two eco-friendly processes including microbial-mediated and metal-free and carbonaceous material processes (GO, N-doped reduced graphene oxide, and N–P-co-doped reduced graphene oxide), a green, brand new, and hybrid hydrocarbon degrader was synthesized. In fact, a new enzymatic biodegradation method of petroleum hydrocarbons including hexadecane and BTEX compounds using crude enzymes obtained from Alcanivorax borkumensis in the presence of undoped and simultaneously doped and reduced carbonaceous materials is reported for the first time. The results indicated that higher efficiency of hydrocarbon enzymatic biodegradation was achieved when simultaneously reduced and doped carbonaceous materials were utilized. Studies showed that by using reduced GOs and doping with N and P, their biodegradation efficiencies improved by increasing the hydrophobic adsorption, interfacial area, and bacterial growth/population as well. Overall, the studies also indicated that our results could be considered as a promising approach in this field due to the ability of hydrocarbon removal in high concentrations (up to 8000 mg L⁻¹ for hexadecane) in a short time (7 days). Total protein and enzyme activity assays were evaluated.