(335n) Draft Tube Biocontactors and Potential Applications IN Proteins Bioseparations

Airlift bioreactor demonstrated a potential for bioseparation of proteins onto a polystyrene based anion exchange resin. Adsorption experiments were conducted in previously tested airlift biocontactor and equivalent shaking flasks. These experiments were done from solutions containing single protein or binary mixture of bovine serum albumin (BSA) and bovine haemoglobin (BHb) with different initial concentrations at pH 7. In single protein adsorption experiments, both proteins were identically adsorbed onto the resin while the presence of BSA in the binary solution hindered the BHb adsorption significantly. Similarly, the inhibition of BSA adsorption from a binary solution containing BHb both at equal fraction was tremendously high. BHb adsorption from shaking flasks was high compared to the airlift biocontactor, which rendered achieving any bioseparation.

Present adsorption results demonstrated that airlift bioreactors have a potential to offer in bioseparation of proteins and improve the efficiency of adsorption. In addition to the hydrophobic interaction forces, compressibility of soft BHb allowed high adsorption, as negatively charged BSA may have adsorbed through electrostatic forces. The homogeneous and lower shear generated in the airlift biocontactor reduced the compressibility of BHb allowing higher BSA adsorption from binary solutions containing BSA and BHb. This caused a higher bioseparation efficiency of both proteins.