New Packing Materials for Bioreactors Based on Coated and Fiber-Reinforced Biocers

Abstract

Stable shaped ceramic materials with embedded living cells that are applicable as biocatalytic packing material in bioreactors can be prepared by modification of the usual silica sol−gel process. The admixture of commercial alumina fibers (2−3 μm in diameter) shows an excellent reinforcing effect. By a simple casting process and drying in air, biocomposite materials with green-body character in any desirable shape are formed. The advantages of the biocers so prepared include high compactness, weak shrinkage during drying, and high mechanical stability. Due to the presence of residual water within the matrix, the incorporated cellular systems are living and show a high biocatalytic activity. Alternatively, biocatalytic packing materials can be fabricated by coating mixtures from aqueous silica nanosols with living cells on differently formed glass substrates. Coated and fiber-reinforced materials are successfully tested for the biodegradation of phenol with immobilized Rhodococcus cells and of glycol mixtures with Aspergillus spores in industrial wastewater.