|
KMID : 1094720090140040419
|
|
Biotechnology and Bioprocess Engineering
2009 Volume.14 No. 4 p.419 ~ p.428
|
|
|
Surface Energetics to Assess Biomass Attachment onto Immobilized Metal-ion Chromatography Adsorbents in Expanded Beds
|
|
Vennapusa Rami Reddy
Aasim Muhammad
Cabrera Rosa
Marcelo Fernandez-Lahore
|
|
|
Abstract
|
|
|
|
Cell-to-support interaction and cell-to-cell agglomeration phenomena have been studied in a model system composed of intact yeast cells and Chelating-StreamlineTM adsorbents. Biomass components and beaded adsorbents were mainly characterized by contact angle determinations with three diagnostic liquids. Complementarily, zeta potential measurements were performed. These experimental values were employed to calculate free energy of interaction versus distance profiles in aqueous media. The effect of immobilized metal-ion type and buffer pH on the interaction energy was evaluated. Calculations indicated that moderate interaction between cell particles and adsorbent beads can develop due to the presence of Cu2+ ions onto the solid phase. The strength of interaction increased with buffer pH, within the range 6.0 to 8.3 e.g. secondary energy pockets increased from |15| to |60| kT. Cell-to-cell secondary energy minimum was ≥ |14| kT showing low-to-moderate tendencies to aggregate, particularly at pH ≥ 8. Extended DLVO predictions were generally confirmed by biomass deposition experiments. However, an exception was found when working with immobilized Cu2+ at pH 8 since yeast cells were able to sequestrate such immobilized ions. Therefore, lower-than-expected values for the depositions coefficient (α) were observed. Understanding biomass attachment onto Chelating supports can help in better design and operate expanded bed adsorption of bioproducts.
|
|
|
KEYWORD
|
|
|
direct sequestration, biomass deposition, surface energetics, bioprocess design, immobilized metal affinity chromatography, expanded bed adsorption
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
 
|