Comparison of phenolic substrate utilization and growth kinetics between immobilized and suspended degradative-bacteria

Establishing if immobilized cells have greater tolerance to aromatic pollut ant chemicals than cells in suspension, is an important target in modelling and designing cell bioreactors. In this paper 4-hydroxyphenylacetic acid m ineralization; the specific 4-hydroxyphenylacetic acid hydroxylase activity ; and the viability in freely suspended and immobilized monocultures of two different strains, Escherichia coli W21 (pGA260) and Klebsiella pneumoniae are compared. The immobilized cells, growing on a ceramic support, exhibit viability and catalytic activity higher than suspended cells. By using a k inetic model for describing CO2 formation, it is demonstrated that immobili zed K. pneumoniae cells are biocatalytically more active than the other sys tems studied.