Immobilization of cells defined by Chibata (1978) as a method for confining or physically placing of microbial
cells in a particular space in which the cells still have the catalytic activity and can be used continuously and
repeatedly. This immobilized cell state that can be in a state of growth, rest (resting) and or the state of autolysis. In
some cases, the microbial immobilized cells were dead, but still show the activity of the enzyme. Advantages
include cell immobilization technique can be used in continuous system, can be used repeatedly on a batch system,
can be used for excretion of secondary metabolites, can protect from interference turbulent flow and can prevent the
interfacial inactivation (Tramper, 1990 in Champagne et al, 1994).