Intracellular-to-extracellular localization switch of acidic lipase in Enterobacter cloacae through multi-objective...

As physiological impairments that require replacement therapy continue to increase, so also does the need for improved production of acidic lipase from new microbial sources. Enterobacter cloacae strain UCCM 00116 produced a novel acidic lipase in kernel oil-processing waste-basal broth with 0.023:1 extracellular: intracellular localization ratio. This research re-directed enzyme localization to the extracellular milieu to reduce recovery cost using multi-objective response surface optimization of medium parameters. Results revealed a 1:0.32 extracellular:intracellular lipase ratio. Product formation kinetics, modeled by the Luedeking-Piret function, showed a significant switch from a completely growth-associated intracellular production to a predominantly non-growth-associated extracellular localization through medium optimization. Aqueous two-phase system purification conditions extracted 95.22% lipase with 72.36 purity, a V_max of 370.37 µmolmin^-1, and a K_m of 0.63 mmol. Enzyme activity was enhanced by K⁺ and Ca²⁺ ions, stable in many organic solvents, except acetone, and had pH and temperature optima at 2.5-3.5 and 50 °C, respectively.