Expanding the Thermomyces lanuginosus lipase repertoire: genome-guided discovery and characterisation of three thermostable lipolytic enzymes

Thermomyces lanuginosus produces one of the most widely used commercial thermostable lipases, including its genetically modified variants. Although these lipases have been used for decades, no other new lipases have been reported from T. lanuginosus. Genome sequencing of this fungus resulted in the identification of additional putative lipases. A comparative sequence analysis revealed distinct differences among these additional lipolytic enzymes, exhibiting minimal sequence identity and similarity to known lipases. Their recombinant expression in Escherichia. coli yielded LipA (176.2 U/mL), LipB (184.1 U/mL), and LipC (181 U/mL). Optimal activity was observed at 60˚C and pH 8. All three enzymes preferred long chain substrates, LipA and LipB favoured p -nitrophenyl palmitate (C16) while LipC preferred p -nitrophenyl stearate (C18). The thermodynamic analysis of these lipases at 60, 70 and 80˚C showed varying deactivation energies (E d ), entropies (ΔS), and enthalpies (ΔH). LipC exhibited the lowest K d values (0.078 to 0.193 h − 1 ), and the highest E d (44.57 kJ mol − 1 ) and t 1/2 (3.59 to 8.91) values. The elevated E d of LipC is therefore consistent with its lower K d values and extended half‑life, supporting its classification as the most thermostable variant in this study. These results were consistent with the in-silico prediction and analysis.