In Silico Approach for Fluorene Biodegradation, and the Impacts of Derivatives on the Environment and Health

Fluorene poses ecological and health hazards that originate from biomass combustion and petroleum. However, some microorganisms can counter fluorene through complex enzymatic degradation pathways. This research aimed to explore the catalytic efficiency of enzymes on metabolites and their toxicity levels throughout the fluorene biodegradation pathway. Several web servers and software were used to characterize them and analyse molecular dockings between ligands and proteins. Fluorene and its metabolites have mild toxicities to the brain, lung, neurons, and kidneys, and consequent endpoints cause mutations, cancer, and ecotoxicity at different levels. The catalytic enzymes are well-folded, single-chained, medium-sized proteins that are acidic, thermostable, and with few exceptions, hydrophilic, cytoplasmic, non-allergenic, and nonvirulent, possessing multiple active sites. The ERRAT, PROCHECK, and VERIFY 3D tools successfully validated the SWISS-modelled 3D structures of proteins. Molecular docking results showed moderate binding affinities between proteins and ligands, ranging from -9.4 to -6.1 kcal/mol, indicating potential activities of the enzymes. This computational study supports the conventional fluorene degradation pathway and may provide a new avenue for further research.