Sodium Caseinate–Enzyme Conjugates as Biocatalysts for Recyclable Pickering Interfacial Biocatalysis

Abstract

Stimuli-responsive Pickering interfacial biocatalysis is a prominent topic in biphasic biocatalysis for its high efficiency and flexible tunability. Herein, we designed CO2/N2-responsive sodium caseinate (NaCas)–enzyme conjugates that acted as both catalytic sites and stabilizers to construct a responsive Pickering interfacial biocatalytic system. The conjugates were prepared by a one-step strategy in which amino groups reacted with carboxyl groups between NaCas and enzymes. In the meantime, NaCas, with a disordered structure, could act as a buffer in the microenvironment to improve enzyme stability in harsh environments. The emulsion system stabilized by horseradish peroxidase (HRP)–NaCas displayed a higher catalytic efficiency and conversion rate compared with the conventional two-phase system, and HRP–NaCas could be easily recycled at least five times by bubbling CO2 and N2. Furthermore, the coupled NaCas system was implemented in Candida antarctica lipase B (CaLB), which extended the excellent interfacial characteristics and application field of NaCas.

Proteinaceous Microsphere-Based Water-in-Oil Pickering Emulsions for Preservation of Chlorella Cells

“…Recently, with the promotion of sustainable development and green chemistry concepts, researchers have shifted their research focus to Pickering emulsions stabilized by bio-based or natural particles [ 42 , 43 , 44 , 45 , 46 ]. Biopolymer-based colloidal particles such as starch, cellulose, and proteins have been widely discovered and developed [ 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. These biomolecule-based colloidal particles have excellent biocompatibility, natural safety, and sustainability, leading to their successful application in the preparation of food-grade Pickering emulsions, the development of vaccine adjuvants, and drug delivery systems.…”