Recovery of β-galactosidase produced by Kluyveromyces lactis by ion-exchange chromatography: Influence of pH and ionic strength parameters

Abstract

The use of β-galactosidase in food products has been a major focus of the industry. Therefore, the development of efficient and inexpensive methodologies to purify it is essential. Thus, this study aimed to recover the enzyme β-galactosidase (β-gal) by ion-exchange chromatography in a fixed-bed column. Batch adsorption tests were performed using four types of adsorbents. The β-gal adsorption capacity in batch mode using Streamline DEAE resin presented the best performance, with a retention capacity of 18.77 ± 0.14 U/g at pH 6.0. A 2² experimental design was applied to optimize the β-gal recovery using an AKTA Start system, evaluating the ionic strength and the pH as process parameters. The results showed that ionic strength exerted a greater influence on fold purification (FP). The β-gal fraction in elution using 0.1-0.4 M of NaCl showed a yield of 51.65 ± 0.17% and FP of 2.00 ± 0.43. Electrophoresis confirmed the β-gal recovery, where an evident band with a molecular weight between 60 and 120 kDa was observed. These results point to the recovery of a stable β-gal of K. lactis with potential industrial applications.

Key words
β-galactosidase; adsorption; Kluyveromyces lactis; ion-exchange chromatography; recovery