Development of a new bioaffinity stationary phase for lactose removal using a lactose-binding lectin immobilized onto polyaniline

The global prevalence of individuals with lactose intolerance and galactosemia has created a new market for commercially available lactose-free food products. In this scenario, the use of systems containing lactose-binding molecules for lactose removal is quite promising. In this work, a new lectin from Brosimum gaudichaudii was purified, characterized and immobilized onto polyaniline aiming to develop a new system for lactose removal through bioaffinity chromatography. The lectin from Brosimum gaudichaudii (brosimin) was purified through sequential size exclusion chromatography, reaching a protein purification of 34-fold. Brosimin was characterized as a lactose-binding ion-independent lectin, with two subunits of 25 kDa and 31 kDa. The best support for brosimin immobilization was found as glutaraldehyde modified polyaniline, reaching 47% of lactose removal from skim bovine milk. Furthermore, considering the upscale process, the use of sequential reactors containing PANIG-brosimin could provide high levels of lactose removal, reaching a product with the requirements to be used by individuals with lactose and/or galactose intolerance.