Multi-substrate kinetic framework and wool-immobilised Pseudomonas fluorescens lipase (WPFL) for solvent-free biocatalysis of terpene esters from rose geranium oil

We present a green, solvent-free enzymatic strategy for the valorisation of rose geranium essential oil into bio-based terpene esters using wool-immobilized Pseudomonas fluorescens lipase (WPFL). Among 30 volatiles, the major constituents citronellol and geraniol were selectively transformed. The process achieved complete conversion of geraniol and 88% conversion of citronellol within 5 hours, doubling productivity relative to conventional solvent-based methods while maintaining efficiency across varied substrate concentrations. Wool, as a renewable and biodegradable support, ensured uniform enzyme distribution and high catalytic stability. Kinetic analysis using specificity constants (kcat/K M ) provided turnover numbers of 5.03 s⁻¹ (geraniol) and 0.25 s⁻¹ (citronellol), establishing the first multi-substrate kinetic framework for essential oil transesterification. Compared to commercial catalysts like Novozym 435, WPFL offers a scalable, cost-effective, and environmentally benign route to sustainable fragrance and flavour esters. Sensory analysis before and after transesterification revealed altered olfactory profiles, highlighting the potential to generate novel fragrance profiles through biocatalysis. This work demonstrates how solvent-free processing, renewable enzyme supports, and kinetic modelling can be integrated to enable efficient, scalable production of bio-based chemicals. • Green solvent-free lipase process converts rose oil to high-value terpene esters • Wool-immobilised P. fluorescens lipase is low-cost, biodegradable and reusable • New, multi-substrate kinetic model quantifies selectivity and catalytic efficiency • Approach adaptable to other terpene-rich essential oils and biomass feedstock