Expanded Bed Recovery of D-2-Chloropropionic Acid Dehalogenase Using TiO2-Densified Cellulose Anion Exchanger1

The TiO2-densified cellulose composite beads were activated by epichlorohydrin and coupled with diethylamine, to function as an anion exchanger for expanded bed chromatography. The adsorbent exhibited a favorable performance of expanded bed adsorption for proteins, and therefore was applied to the expanded bed recovery of D-2-chloropropionic acid dehalogenase directly from the unclarified homogenate of Pseudomonas sp. NT21. The binding capacity of the dehalogenase was found to be 8.54U·ml−1 adsorbent, and two active peaks were eluted respectively at 0.15mol·L−1 and 0.3mol·L−1 (NH4)2SO4. The result indicated that the overall enzyme yield was 68%, with a purification factor of 22. In comparison to other recovery processes, the yield of the expanded bed process rises at least 70%, simultaneously saving a great deal of operation time and costs.