Biosynthesis of cyclodextrin glucanotransferase by the chitosanbead immobilized cells of Bacillus sp. DSM 2523

In the present study, Bacillus sp. DSM 2523 cells were immobilized in chitosan gel beads, crosslinked with sodium tripolyphosphate (TPP), which can be a promising method for repeated cyclodextrin glucanotransferase (CGTase) production due to the high stability of the beads. Thepurpose of this investigation was to optimize the CGTase production by entrapped cells of the test bacterium in chitosan gel beads in shake flasks. The activity of the enzyme produced from the immobilized cells was compared to that of the free cells. Moreover, the optimization was carried out with respect to matrix concentration and bead diameter. Increase in the chitosan concentration, caused decrease in the enzyme activity. On the other hand, beads made of lower chitosan concentrations, were too fragile and this led to increase of the free cell in the medium because of the cells growth. The maximum CGTase activity of immobilized cells was obtained by applying beads made by using 2 %w/v chitosan solution and have 2.5 mm diameter.

Keywords:

Cyclodextrin glucanotransferase , Chitosan , Immobilization , Cell entrapment