Adsorptive immobilization of rhodococcal cells in hydrophobized derivatives of wide-pore poly(acrylamide) cryogel

Adsorption of Rhodococcus ruber cells on columns with poly(acrylamide) cryogel (cryoPAAG) partially hydrophobized by different quantities (0.2, 1, and 5, mol %) of chemically grafted n-dodecane residues has been studied. The adsorption capacity (1.1 × 10⁹ cells/g) of gel carrier for rhodococcal cells and the optimal content (1 mol %) of hydrophobizing groups were determined. The respirometric method showed the high catalytic activity and functional stability of immobilized bacterial cells. Respiratory activity of immobilized rhodococci in the presence of a model mixture of oil hydrocarbons exceeded the respective parameter for free cells by 12–17%. Viability of rhodococcal cells adsorptionally fixed in hydrophobized cryoPAAG was maintained at a level of 93–95% after a half-year period of storage. The results may be used for development of immobilized biocatalyst for directed transformation of hydrocarbon compounds and biological purification of oil-polluted water.