New composite biocarriers engineered to contain adsorptive and ion-exchange properties improve immobilized-cell bioreactor process dependability.

Novel biocarriers that combine the adsorptive properties of activated carbon with the ion-exchange properties of zeolite-based type Z inorganic oxide biocarriers (D. R. Durham, L. C. Marshall, J. G. Miller, and A. B. Chmurny, Appl. Environ, Microbiol. 60:3329-3335, 1994.) were developed. These biocarriers, designated Type CZ, possess fundamental properties that heretofore have not been described for available microbial immobilization matrices. Type CZ biocarriers provide an environment that promotes dense microbial colonization and maintains bioreactor productivity by buffering immobilized microorganisms from unfavorable operating conditions. Data demonstrating protection of immobilized bacteria from organic shock loads and extended pH shocks are presented. In addition, bioreactors containing the composite Type CZ biocarriers continue to remove waste stream contaminants during periods of oxygen deprivation and nutrient limitation.