Location: Bioenergy Research Unit
Title: Cloning and sequencing of CGTase genes of two Thermoanaerobacter strains Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 12, 2012
Publication Date: August 16, 2012
Citation: Avci, A., Nichols, N.N., Saha, B.C., Cotta, M.A., Donmez, S. 2012. Cloning and sequencing of CGTase genes of two Thermoanaerobacter strains [abstract]. Society for Industrial Microbiology and Biotechnology. Paper No. P43. Technical Abstract: Cyclodextrin glycosyltransferase (CGTase; EC 220.127.116.11) is an important industrial enzyme that catalyzes the formation of cyclodextrins from starch and related substrates via transglycosylation reaction. Cyclodextrins are cyclic oligosaccharides, composed of 6,7 or 8 glucose units, which are used in various industrial fields due to their capacity for inclusion complex formation. Although there are numerous Bacillus species identified as CGTase producers, thermophilic enzymes are advantageous for the industrial production as starch liquefaction requires higher temperatures. We have isolated two CGTase-producing, thermophilic anaerobic bacteria belonging to the genus Thermoanaerobacter, from an oil well in Turkey. The CGTase enzymes from these two bacteria have optimum activity at 80-85 oC and 100% stability at 80 oC for 24 h. Phylogenetic and biochemical properties of the bacteria together with enzymatic characteristics were presented elsewhere. In this study, the genes encoding the CGTases from Thermoanaerobacter sp. P4 and Thermoanaerobacter sp. 5K were cloned and sequenced. The genes from strains P4 and 5K encode 685 and 682 amino acids, respectively, and the two amino acid sequences are 96.5% identical. Identities of the deduced amino acid sequences from strains P4 and 5K with Thermoanaerobacter sp. ATCC53627 are 97.3 and 96.6 %, respectively; identities with Thermoanaerobacterium thermosulfurigenes are 91.2 and 89.4 %, respectively. The 3D structures of the proteins were examined using the I-TASSER algorithm for automated protein structure prediction.