Boron based separations for in situ recovery of L-erythrulose from transketolase-catalyzed condensation

Abstract

In this article we report on the application of in situ product removal (ISPR) (the concurrent recovery of a product during the product formation process) as a means of improving the productivity of bioconversions. The Escherichia coli transketolase‐catalyzed condensation of glycolaldehyde with β‐hydroxypyruvate to yield L‐erythrulose (and carbon dioxide) was chosen as a model system. Those ISPR methods based on phenylboronate‐diol interactions showed greatest potential for use as a selective means of removing L‐erythrulose from the reaction medium. Soluble, insoluble, and immobilized boronates were investigated. Concentrations of free phenylboric acid of 100 mM and above were toxic to transketolase, thus rendering the use of these methods unsuitable for ISPR. However, one of the immobilized phenylboronate resins (Affi‐Gel 601®) was not toxic to the enzyme, although significant levels of nonspecific binding of both substrates were observed. When ISPR was performed on the model reaction using this resin with substrate feeding, it proceeded to completion. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 345–351, 1997.

Substrate Supply for Effective Biocatalysis

“…Of particular importance is its affinity for both the substrate and the product. It is crucial that the resin does not bind too tightly so as to lower bioavailability of the substrate even further (66,73). Some enzymes or cells may exhibit an attraction to certain resin particles, and a careful screening process should be employed to avoid catalyst adsorption (22).…”

A Reusable Interface Constructed by 3‐Aminophenylboronic Acid‐Functionalized Multiwalled Carbon Nanotubes for Cell Capture, Release, and Cytosensing

“…The first reports of boric12, 13 and boronic acid13 forming compounds with saccharides appeared in the 1950s, and this pioneering work has since attracted considerable attention. To date, boronic acid chemistry and the pH‐dependent reversible formation of these complexes have been exploited in a number of applications including affinity chromatography to selectively capture and separate cis‐diol‐containing biomolecules,14, 15 such as glycoproteins,16–22 glycosylated peptides,23 enzymes,24 carbohydrates,25, 26 catechols,27, 28 and nucleosides;29–31 capillary electrophoresis,32 aqueous sugar sensors,33 and glycoprotein‐immobilization in cellulose beads 34. Furthermore, because of the wide variety of poly‐ and oligosaccharides localized on the walls of microbial and animal cells which can be targeted by sugar‐specific ligands, we can use the sugar‐specific antibodies and lectins for controllable attachment and detachment of cells 35.…”

Improving process conditions of hydroxytyrosol synthesis by toluene-4-monooxygenase

“…Use of boric acid beads was investigated by Chauhan et al for the recovery of l-erythrulose [22]. Although the recovery yields were not addressed by the authors, calculations made out of the reported data give recovery yields of ∼60%.…”

“…Although the recovery yields were not addressed by the authors, calculations made out of the reported data give recovery yields of ∼60%. Interestingly, the yields reported for the biotransformation with the beads (as ISPR concept) were the same and even lower than those obtained without the beads (for example, reaction yield of 87% was reported in a fed-batch reaction with ISPR, compared to 100% yield without ISPR) [22]. Nevertheless, employing the beads for the biotransformation facilitated the potential recovery of the product.…”