Industrial Biotransformations

Cyclodextrin glycosyltransferase
Bacillus circulans
● The separation is established by selective adsorption of α- and β-cyclodextrins on chitosan
beads with appropriate ligands. α-Cyclodextrins are selectively interacted with stearic acid and
β-cyclodextrins with cyclohexanepropanamide-n-caproic acid. The adsorption selectivity is
almost 100 %. In the case of the β-cyclodextrins a capacity of 240 g · L –1 gel bed is reached.
● The process data given here are related to the production of α-cyclodextrins.
● Before entering the adsorption column the temperature is lowered to 30 °C for effective
adsorption. At this temperature almost no cyclodextrins are formed during circulation. Before
re-entering the main reactor the temperature of the solution is again adjusted to 55 °C by using
the energy of the reaction solution leaving the reactor.
● To prevent adsorption of the cyclodextrin glycosyltransferase in the α-cyclodextrin adsorbent
3 % w/v NaCl is added. CDs adsorbed on the resin through ionic bonds are easely removed by
4 % NaCl (Okabe et al., p. 115).
3) Flow scheme
Fig. 2.4.1.19 – 2
4) Process parameters
yield: 22.3 % (α-cyclodextrin); 10.8 % (β-cyclodextrin);
5.1 % (γ-cyclodextrin)
chemical purity: 94.9 %
reactor type: batch
down stream processing: chromatography and crystallization
enzyme supplier: Amano, Japan
company: Mercian Co., Ltd., Japan
5) Product application
EC 2.4.1.19
● Cyclodextrins serve as molecular hosts and are used in the food industry for capturing and
retaining flavors. They are also used in the formulation of pharmaceuticals.
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