This invention relates to the immobilization of biologically active materials, e.g. bacteria, and in particular to the immobilization of such materials in a polymeric gel matrix comprising chitosan (a high molecular weight polysaccharide) and lignosulphonate.
Biotransformation of chlorinated aliphatics is a multi-step process that can be carried out under both aerobic and anaerobic conditions. The rate of anaerobic degradation of these compounds decreases with the removal of chlorine from the molecules while the degradation rate under aerobic conditions increases (Gerritse et al, 1995).sup.1. Thus, the removal of chlorinated aliphatics is a good candidate for the coupling of aerobic and anaerobic biotransformations in an immobilized system.