Immobilization of microbial cells in crosslinked, prepolymerized, linear polyacrylamide gels: Antibiotic production by immobilized Streptomyces clavuligerus cells

A mild new method for the immobilization whole microbial cells has been developed. Cells were suspended in a solution of preformed, linear, water‐soluble Polyacrylamide chains, partially substituted with acylhydrazide groups. The Prepolymerized backbone polymer was crosslinked, in the presence of viable cells, by stoichiometric amounts of dialdehydes such as glyoxal, glutardialdehyde, and period ate‐oxidized polyvinyl alcohol. The crosslinking reaction, carried out in cold, neutral physiological conditions resulted in cells entrapped in gels with physical properties similar to those of the common Polyacrylamide gels. However, cell damage generally caused by the acrylamide monomer was avoided. Resting Streptomyces clavuligerus cells, possessing a high capacity for antibiotic production, were entrapped according to this procedure. These immobilized cells produced cephalosporins continuously for 96 h with yields similar to those of free resting cells. The same cells, when immobilized by direct polymerization acrylamide monomers, yielded significantly lower amount of antibiotics.