Downstream processing of L-asparaginase through silica-based supported ionic liquid-like phase materials

Abstract

L-asparaginase (ASNase) is an amidohydrolase enzyme widely applied as an anticancer agent in the treatment of lymphoproliferative disorders, e.g., acute lymphoblastic leukemia (ALL), lymphomas, and natural killer cell tumors, as an acrylamide reduction agent in starch-rich foods cooked at high temperatures, and as a biosensor for L-asparagine detection and monitoring. ASNase is extensively distributed in nature, e.g., microorganisms, plants, and animals; however, most commercial ASNase are from recombinant microorganisms, whose production can be performed through fermentation. Nonetheless, its downstream processing accounts for up to 80% of total production cost. Thus, the development of a novel cost-effective purification process is of emerging concern to allow its widespread use. The main goal of this work is to develop a novel cost-effective downstream process for ASNase from complex recombinant Bacillus subtilis cell lysate obtained through ultrasound sonication. Silica-based supported ionic liquid-like phase (SSILLP) materials comprising quaternary ammonium and chloride as counterions, previously used to produce ASNase-SSILLP bioconjugates through simple adsorption of commercial ASNase, were investigated as cost-effective ASNase purification supports through a simple adsorption method. Specific experimental conditions, e.g., medium pH and solid/liquid ratio, were optimized through Response Surface Methodology regarding ASNase purity. Through this approach, process costs, energy consumption, and waste produced, might be significantly reduced, leading to the ASNase price decrease, thereby enabling its wider application.