Jornal de tecnologia microbiana e bioquímica

Abstrato

Surface Modifications for Controlled and Optimized Cell Immobilization by Adsorption: Applications in Fibrous Bed Bioreactors Containing Recombinant Cells

Peter Kilonzo and Maurice Bergougnou

The effects of surface properties of S. cerevisiae strains 468/pGAC9 and 468 on adhesion to polyethylenimine (PEI) and/glutaraldehyde (GA) pretreated cotton (CT), polyester (PE), polyester + cotton (PECT), nylon (NL), polyurethane foam (PUF), and cellulose re-enforced polyurethane (CPU) fibers were investigated. Process parameters (circulation velocity, pH, ionic strength, media composition and surfactants) were also examined. 80, 90, and 35% of the cells were adsorbed onto unmodified CT, PUF and PE, respectively. PEI-GA pre-treated CT and alkali treated PE yielded 25% and 60% cell adhesion, respectively. Adsorption rate (Ka) ranged from 0.06 to 0.17 for CT and 0.06 to 0.16 for PE at varied pH. Adhesion increased by 15% in the presence of ethanol, low pH and ionic strength, and decreased by 23% in the presence of yeast extract and glucose. Shear flow and 1% Triton X-100 detached 62 and 36% nonviable cells from PE and CT, respectively, suggesting that cell immobilization in fibrousbed bioreactors can be controlled to optimize cell density for long-term stability.