Abstract: Antimicrobial preservative compositions that can be incorporated in products to be preserved are disclosed herein. The disclosed compositions include immobilized biocidal enzymes, such as cross-linking enzymes or active enzymes falling into the zymogen-class, for the purpose of modifying amino acid residues on a protein or binding a molecule of interest to a protein. The compositions include enzymes that are immobilized on a polymeric solid support, which improve the shelf life of the enzyme and protect the enzyme from auto-cross-linking or other deterioration over extended storage periods. Also disclosed are methods of increasing the self-like of products, such as personal care, household and industrial products, by incorporating an effective amount of the disclosed compositions into the product.