Cyclodextrins are non-reducing cyclic glucose oligosaccharides resulting from the cyclomaltodextrin glucanotransferase (E.C. 2.4.1.19; CGTase) catalyzed degradation of starch. Their structures have been reviewed. There are three common cyclodextrins with 6, 7 or 8 D-glucopyranonsyl residues (α-, β-, and γ-cyclodextrin respectively) linked by α-1,4 glycosidic bonds. The glucose residues have the...

The objective was to compare the action of different hydrolases for producing porous corn starches. Amyloglucosidase (AMG), α-amylase (AM), cyclodextrin-glycosyltransferase (CGTase) and branching enzyme (BE) were tested using a range of concentrations. Microstructure, adsorptive capacity, pasting and thermal properties were assessed on the porous starches. SEM micrographs showed porous structur...

A heterologous signal peptide (SP) from Bacillus sp. G1 was optimized for secretion of recombinant cyclodextrin glucanotransferase (CGTase) to the periplasmic and, eventually, extracellular space of Escherichia coli. Eight mutant SPs were constructed using site-directed mutagenesis to improve the secretion of recombinant CGTase. M5 is a mutated SP in which replacement of an isoleucine residue i...

An extractive bioconversion with Bacillus cereus cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) in aqueous two-phase system (ATPS) was investigated for the synthesis and recovery of cyclodextrins (CDs). Optimum condition for the extractive bioconversion of CDs was achieved in ATPS consisted of 7.7% (w/w) polyethylene glycol (PEG) 20,000 and 10.3% (w/w) dextran T500 with volume ratio (VR...

A gene encoding a cyclodextrin glucanotransferase (CGTase) from Thermococcus kodakaraensis KOD1 (CGT(Tk)) was identified and characterized. The gene (cgt(Tk)) encoded a protein of 713 amino acid residues harboring the four conserved regions found in all members of the alpha-amylase family. However, the C-terminal domain corresponding to domain E of previously known CGTases displayed a completel...

The extremely thermophilic anaerobic archaeon strain B1001 was isolated from a hot-spring environment in Japan. The cells were irregular cocci, 0.5 to 1.0 micrometers in diameter. The new isolate grew at temperatures between 60 and 95 degrees C (optimum, 85 degrees C), from pH 5.0 to 9.0 (optimum, pH 7.0), and from 1.0 to 6.0% NaCl (optimum, 2.0%). The G+C content of the genomic DNA was 43.0 mo...

Cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) production using new alkaliphile Microbacterium terrae KNR 9 was investigated by submerged fermentation. Statistical screening for components belonging to different categories, namely, soluble and raw starches as carbon sources, complex organic and inorganic nitrogen sources, minerals, a buffering agent, and a surfactant, has been carried ou...

Small molecule inhibitors play an essential role in the selective inhibition of enzymes associated with human infection and metabolic disorders. Targeted enzymes may evolve toward inhibitor resistance through selective incorporation of mutations. Acquisition of insensitivity may, however, result in profound devolution of native enzyme function and stability. We therefore investigated the conseq...

The crystal structure of the cyclodextrin glycosyltransferase (CGTase) from the thermophilic microorganism Thermoanaerobacterium thermosulfurigenes EM1 has been elucidated at 2.3 A resolution. The final model consists of all 683 amino acid residues, two calcium ions and 343 water molecules, and has a crystallographic R-factor of 17.9% (Rfree 24.9%) with excellent stereochemistry. The overall fo...

Cyclodextrin glycosyltransferase (CGTase) is a multifunctional enzyme that hydrolyzes the <em>α</em>-glycosidic bond between two sugar molecules and synthesizes cyclodextrins (CDs) other transglycosylation products. It ubiquitously present extracellular offers CGTase-producing organism sole right onto starch substrates over microbes. The review provides brief account of diversity am...