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Compatibility of column inlet and adsorbent designs for processing of corn endosperm extract by expanded bed adsorption
Author(s) -
Menkhaus Todd J.,
Glatz Charles E.
Publication year - 2004
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20117
Subject(s) - endosperm , adsorption , inlet , elution , chromatography , volumetric flow rate , chemistry , clogging , matrix (chemical analysis) , expanded bed adsorption , materials science , chemical engineering , analytical chemistry (journal) , biochemistry , organic chemistry , thermodynamics , history , archaeology , mechanical engineering , physics , engineering
Corn has emerged as a viable host for expression of recombinant proteins; targeted expression to the endosperm has received particular attention. The protein extracts from corn endosperm differ from those of traditional hosts in regard to the nature of residual solids and extracted matrix contaminants. Each of these differences presents reasons for considering expanded bed adsorption for product capture and new considerations for limitations of the method. In this work three inlet‐flow distribution devices (mesh, glass ballotini, and localized mixing) and six adsorbents with different physical (size and density), chemical (ligand), and base matrix properties were evaluated to determine conditions compatible with processing of crude corn endosperm extract by expanded bed adsorption. Of the inlet devices evaluated, the design with localized mixing at the inlet (as produced commercially by UpFront Chromatography A/S, Copenhagen, DK) allowed solids up to 550 μm into the column without clogging for all flow rates evaluated. A mesh at the inlet with size restriction of either 50 μm or 80 μm became clogged with very small corn particles (< 44 μm). When glass ballotini was used, large particles (550 μm) passed through for high flow rates (570 cm/h), but even small (< 44 μm) particles became trapped at a lower flow rate (180 cm/h). The physical and chemical properties of the resin determined whether solids could be eluted. The denser UpFront adsorbents allowed for complete elution of larger and more concentrated corn solids than the currently available Amersham Streamline adsorbents (Amersham Biosciences, Piscataway, NJ) as a result of the former's higher flow rate for the desired 2× expansion (570 cm/h for UpFront vs. 180 cm/h for Streamline). All corn solids < 162 μm eluted through nonderivatized UpFront resin. Larger corn solids began to accumulate due to their elevated sedimentation velocities. Feeds of < 44 μm solids at 0.45% and 2.0% dry weight successfully eluted through ion exchange adsorbents (DEAE and SP) from UpFront. However, significant accumulation occurred when the solids size increased to a feed of < 96 μm solids, thus indicating a weak interaction between corn solids and both forms of ion exchange ligands. Expanded beds operated with Streamline ion exchange adsorbents (DEAE and SP) did not allow full elution of corn solids of < 44 μm. A hyperdiffuse style EBA resin produced by Biosepra (Ciphergen Biosystems, Fremont, CA) with CM functionality showed a severe interaction with corn solids that collapsed the expanded bed and could not be eliminated with elevated flow rates or higher salt concentration. © 2004 Wiley Periodicals, Inc.