Immobilisation of cyclodextrin glucanotransferase from Bacillus circulans ATCC 21783 on purified seasand

Abstract

Cyclodextrin glucanotransferase (CGTase) from Bacillus circulans (ATCC 21783) was immobilised on a silica-based support: purified seasand. Although adsorption of 98% was achieved, considerable desorption was encountered. This problem was minimised by crosslinking the adsorbed enzyme with glutaraldehyde. The immobilised enzyme after crosslinking could be used repeatedly for cyclodextrin (CD) production in a batch process. The activity retention was 80% at the end of the eighth cycle. The immobilised enzyme showed a shift in the pH optimum towards the alkaline side and also an improvement in the pH stability compared to the free enzyme. It catalysed the formation of beta-CD as a major product. A significant amount of alpha-CD production was also observed on prolonged incubation.

Cyclodextrin glucanotransferase production by cell biocatalysts of alkaliphilic bacilli

“…their properties like activity, resistance to inhibition by reaction products, selectivity towards non-natural substrates [14]. Different approaches have been applied for the immobilization of CGTases, based on adsorption [15], entrapment [16] or covalent binding [17][18][19]. Immobilization by physical adsorption or entrapment is generally unsuitable because the enzyme readily leaks from the support during the reaction.…”

Immobilized Cells of Bacillus circulans ATCC 21783 on Palm Curtain for Fermentation in 5 L Fermentation Tanks

“…A large volume of literature has reported the production of CGTase based on cell immobilization. Organic matrices such as loofa sponge, alginate gel, agar gel, chitosan, synthetic adsorption resin [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], inorganic matrices like SiO 2 /TiO 2 , SiO 2 /MnO 2 and seas and could also be used as immobilize matrices [ 16 , 17 , 24 ]. Vassileva et al [ 20 ] used agar gel to immobilize Bacillus alkaliphilus ATCC 21783, and the residual enzyme activity of the immobilized cells ranged from 90% to 95% after cultivating for 240 h in a fluidized bed reactor.…”

Immobilization and Stabilization of a Cyclodextrin Glycosyltransferase by Covalent Attachment on Highly Activated Glyoxyl-Agarose Supports

“…However, immobilized enzymes are an alternative to allow the recovery and reuse of the biocatalysts in large‐scale applications, reducing the costs and simplifying product purifications (Rosevear, 1984; Bickerstaff, 1997; Hartmeier, 1995; Katchalski‐Katzir, 1993; Cao et al, 2003; Cao, 2005). Thus, several CGTases have been immobilized using different supports and immobilization methods (Kato and Horikoshi, 1984; Abdel‐Naby, 1999; Martin et al, 2002, 2003; Lyer, 2003; Steighardt and Kleine, 1993). However, when an immobilized biocatalyst is prepared, it should be considered that the main goal of enzyme immobilization should be the reuse of the biocatalyst, and this means that the final biocatalyst should be as stable as possible to be reused for many reaction cycles.…”