The high level of biocatalysts such as microbial cells and enzymes plays an
important role in increasing the productivity of a bioreactor. The beads e
ntrapped with microbial cells are not strong enough for longterm use. The s
mall void space of polymer matrix and the leakage of cells limit a final ce
ll loading in the beads. The recent success of encapsulating microbial cell
s makes it possible to prepare dense biocatalyst composed of recombinant mi
crobial cells. In addition to encapsulating microbial cells, immobilization
of animal and plant cells in capsules is also briefly described. (C) 2000
Elsevier Science Inc. All rights reserved.