Scientists engineered a bacterial enzyme from Pseudomonas to metabolize drug compounds like human liver enzymes do, achieving dramatic activity improvements. The modified toluene o-xylene monooxygenase (ToMO) variant I100V/E103T showed 49-fold higher activity toward chlorzoxazone and perfectly mimicked human liver specificity for acetanilide metabolism, producing 100% of the same metabolite (4-AAP) that human enzymes generate. Another variant processed resveratrol 34-fold more efficiently than the native enzyme. This represents a significant advance in biotechnology's quest to replace expensive and ethically complex human liver preparations used in drug development. Pharmaceutical companies currently rely on human liver microsomes costing thousands of dollars per gram to predict how new drugs will be metabolized in patients. These engineered bacterial enzymes could provide a renewable, consistent alternative for drug metabolism studies, potentially accelerating pharmaceutical research while reducing costs. The technology addresses a critical bottleneck in drug development where understanding metabolic pathways determines safety and efficacy. While the current activity rates remain lower than human enzymes, the dramatic fold-improvements achieved through targeted mutations suggest further optimization could yield commercially viable alternatives to human-derived systems.