Nuclease p1 immobilized on deae cellulose

Recent advances in β-galactosidase and fructosyltransferase immobilization technology

The highly demanding conditions of industrial processes may lower the stability and affect the activity of enzymes used as biocatalysts. Enzyme immobilization emerged as an approach to promote stabilization and easy removal of enzymes for their reusability. The aim of this review is to go through the principal immobilization strategies addressed to achieve optimal industrial processes with special care on those reported for two types of enzymes: β-galactosidases and fructosyltransferases. The main methods used to immobilize these two enzymes are adsorption, entrapment, covalent coupling and cross-linking or aggregation (no support is used), all of them having pros and cons. Regarding the support, it should be cost-effective, assure the reusability and an easy recovery of the enzyme, increasing its stability and durability. The discussion provided showed that the type of enzyme, its origin, its purity, together with the type of immobilization method and the support will affect the performance during the enzymatic synthesis. Enzymes' immobilization involves interdisciplinary knowledge including enzymology, nanotechnology, molecular dynamics, cellular physiology and process design. The increasing availability of facilities has opened a variety of possibilities to define strategies to optimize the activity and re-usability of β-galactosidases and fructosyltransferases, but there is still great place for innovative developments.

Biosensor based on electrospun blended chitosan-poly (vinyl alcohol) nanofibrous enzymatically sensitized membranes for pirimiphos-methyl detection in olive oil

An ultra-sensitive electrochemical biosensor was successfully developed for rapid detection of pirimiphos-methyl in olive oil, based of genetically-engineered acetylcholinesterase (AChE) immobilization into electrospun chitosan/poly (vinyl alcohol) blend nanofibers. Due to their unique properties such as spatial structure, high porosity, and large surface area, the use of nanofibers allowed improving the biosensor response by two folds. The developed biosensor showed a good performance for detecting pirimiphos-methyl, with a limit of detection of 0.2nM, a concentration much lower than the maximum residue limit allowed set by international regulations (164nM). The biosensor was used for the detection of pirimiphos-methyl in olive oil samples after a simple liquid-liquid extraction, and the recovery rates were close to 100%.