Genetic and functional characterization of multiple thermophilic organosulfur-removal systems reveals desulfurization potentials for waste residue oil cleaning

Abstract

Heavy oil and petroleum refining residues usually contain high concentrations of recalcitrant hazardous organosulfur compounds, causing long-term serious global environmental pollution during leakage and combustion. Research conducted here identified a unique thermophilic bacterium Parageobacillus thermoglucosidasius W-36 with the notable ability of waste residue oil desulfurization, utilization and tolerance of multiplex hazardous organosulfur pollutants. Genome information mining revealed multiple desulfurization systems in three organosulfur-utilizing gene clusters. Enzymatic characterization, phylogenetic relationships, transcriptional performance and structural prediction indicated four novel key monooxygenases for diverse organosulfur removal. Importantly, all monooxygenases shared obvious commonalities in the predicted tertiary structure backbone and catalytic characteristics of C-S bond cleavage, implying the potential of genetic engineering for broad-spectrum hazardous organosulfur removal. Therefore, this work demonstrated the important application potential of thermophilic bacteria as a promising alternative biodesulfurization way for waste residue oil cleaning.