Lipase purification using ionic liquids as adjuvants in aqueous two-phase systems

Abstract

ARTICLE This journal isAqueous two-phase systems (ATPS) are efficient, environmentally friendly, and "biocompatible" separation processes, which allow the recovery of enzymes. The most common systems are based on polymers and salts, and recently, to overcome the low polarity difference between the phases of the polymeric systems, ATPS based on ionic liquids (ILs) were proposed and have been successfully applied on the field. This work discusses the use of imidazolium-based ILs not as phase forming compounds but as adjuvants (5 wt%) in ATPS of polyethylene glycol systems (1500, 4000, 6000 and 8000 g.mol -1 ) with potassium phosphate buffer at pH 7, in the extraction and purification of a lipase produced by submerged fermentation by Bacillus sp. ITP-001. An initial optimization study was carried with the commercial lipase B from Candida antarctica (CaLB) allowing to further purify the commercial CaLB (Purification Factor = 5.2). Using the optimized conditions, a Purification Factor of 245 for the lipase from Bacillus sp. ITP-001 was achieved with 1-hexyl-3-methyl imidazolium chloride. The high purification factor is a consequence of the favorable interactions between the IL and the contaminant proteins that migrate for the PEG-rich phase, where the IL also concentrates preferentially, while the enzyme remains in the saltrich phase.

Aqueous immiscibility of cholinium chloride ionic liquid and Triton surfactants

“…Traditionally, the most common combination was a polymer and a salt. However, since 2003, when Rogers et al [9] reported the ability of ionic liquids to trigger phase disengagement, many authors have applied this kind of systems for the separation of a variety of biomolecules like enzymes [10,11], antioxidants [12] or alkaloids [13], among others. Several reasons justify the interest in applying ionic liquid-based ABS in the extraction of this type of molecules, e.g.…”

Understanding the effect of ionic liquids as adjuvants in the partition of biomolecules in aqueous two-phase systems formed by polymers and weak salting-out agents

“…However, due to the high solubility of most ILs in water at room temperature, usually large concentrations of salts are required to promote the ATPS formation, turning these processes more expensive and less sustainable. The use of small quantities of ILs as adjuvants in polymer-based ATPS appears as an alternative to overcome these difficulties [7,11,16–19]. …”

“…It was shown that the ILs have a minor effect upon the ATPS formation, and that the partition coefficients values obtained in the systems with ILs are lower than in systems without them. The same authors [16] studied the extraction of lipase produced by submerged fermentation by Bacillus sp. ITP-001 using imidazolium-based ILs as adjuvants (5 wt%) in ATPS composed of PEG (1500, 4000, 6000 and 8000) and potassium phosphate buffer at pH 7.…”

Selective and mild fractionation of microalgal proteins and pigments using aqueous two‐phase systems

“…Thus, IL‐ATPSs potentially have a higher selectivity, flexibility and can provide more efficient separations than commonly used ATPSs composed of polymer‐polymer or polymer‐salt . However, reports on integrated separation processes of biomolecules from biomass using ATPSs and IL‐ATPSs are limited . The application of IL‐ATPSs is generally studied using pure biomolecules (e.g.…”