2017-02-20 · α-CGTase activity. The α-CGTase cyclization activity was measured using an assay similar to that described above for β-CGTase activity. A 0.1 mL aliquot of appropriately diluted crude enzyme was added to 2 mL of preheated 2% (w/v) soluble starch dissolved in 25 mM phosphate buffer (pH 5.5).

Cyclodextrin glucanotransferase (CGTase, EC. 2.1.1.19) produced using new alkaliphile Microbacterium terrae KNR 9 has been purified to homogeneity in a single step by the starch adsorption method. The specific activity of the purified CGTase was 45 U/mg compared to crude 0.9 U/mg.

The beads were washed with 25 ml of saline, phosphate buffer (0Æ01mol l)1,pH6Æ5) and dis-tilled water under sterile conditions and transferred to 50 ml of fresh medium to start new cycle. In continuous fermentation using bioreactor The bioreactor is a glass column of 1Æ8 cm diameter and 32Æ0 cm long. Both enzymes also hydrolyzed α-, β-, and γ-cyclodextrin. Very interestingly, AmyA, but not AmyB, displayed high transglycosylation activity on maltooligosaccharides and also had significant β-cyclodextrin glycosyltransferase (CGTase) activity. CGTase activity has not been reported for typical α-amylases before.

Cgtase activity

A CGTase with high coupling activity using γ-cyclodextrin isolated from a novel strain clustering under the genus Carboxydocella. Gulshan Kazi, Zubaida LU; Lundemo, Pontus LU; Fridjonsson, Olafur H; Hreggvidson, Gudmundur O; Adlercreutz, Patrick LU and Nordberg Karlsson, Eva LU () In Glycobiology 25 (5). p.514-523 Activity and stability characteristics of an alkaline active cyclodextrin glycosyltransferase (CGTase) enzyme from the alkaliphilic Bacillus agaradhaerens LS-3C strain are reported. The enzyme displays unusually high amylolytic activity in relation to the cyclization activity. The standard CGTase activity assays described above was used to determine the residual activity of each enzyme (Jeang et al.

inactivated by heat and is removed completely during the a-CD production . process. DNA from the CGTase source organism (E.

CGTase activity produced from Bacillus circulans DF 9R was optimised in shake flasks using a combination of conventional sequential techniques and statistical experimental design. Effects of nutrients, including several carbon, nitrogen and mineral sources, were assayed.

One unit of enzyme activity was defined as the amount of enzyme that forms 1 μmol of γ-CD from soluble starch in 1 min. Alkaline phosphatase was assayed by the method of Yamane et al.

CGTase activity assay (hydrolytic activity): The starch hydrolyzing activity of CGTase was assayed using the method of Shiosaka and Bunya14, based on the

CGTase activity was assayed as described by Kato and Horikoshi . One unit of enzyme activity was defined as the amount of enzyme that forms 1 μmol of γ-CD from soluble starch in 1 min. Alkaline phosphatase was assayed by the method of Yamane et al. [ 9 ]. CGTase, was selected from B. cereus YUPP-10 by a constructed fos-mid library.

[ 9 ]. The CGTase activity was increased in the presence of metal ions (5 mM): Ca+2 (130 %), Mg+2 (123 %), Mn+2 (119 %) and Co+2 (116 %). The enzyme activity was strongly inhibited in the presence of Hg+ The β-CGTase from alkalophilic Bacillus sp. N-227 was separately mutagenized to give three site-directed β-CGTase mutants, Y127F, R254F and D355R, that showed enhanced cyclization activity towards a starch substrate from 1.64 to 2.1-folds. Kinetic studies indicate that the mutants had higher affinity towards the substrate than the wild type The optimum temperature of CGTase activity increased from 50 to 60 °C after the stabilizer application. The stabilizer was applied to cyclodextrin production, and it resulted in enhanced CGTase activity, which showed higher increases of starch to CD conversion at 60 and 90 °C.
Parkeringsbolaget gbg

We have determined the 2.0 and 2.5 Angstrom X-ray structures of E257A/D229A CGTase in complex with maltoheptaose and maltohexaose. At this point the total soluble γ-CGTase activity had reached 5.51 U·mL − 1. In addition, the ratio of extracellular γ-CGTase activity to total γ-CGTase activity decreased from 71.7 to 55.0% when the concentration of β-cyclodextrin increased from 0 to 10 mM.

The activity of CGTase varied from 22 to 210 dilutions for all strains. The effect of pH on CGTase activity was analyzed over the pH range of 4.5-10.5, under standard conditions (Fig CGTase activity (circle), pH (triangle) and total reducing sugars concentration (square) versus time for enzyme production with immobilized Bacillus firmus strain 37 on bone charcoal. Results: Using the enzyme β-cyclodextrin glycosyltransferase (β-CGTase) as a reporter protein and B. subtilis CCTCC M 2016536 as the host, nine plasmids equipped with single promoters were screened using shake-flask cultivation. The plasmid containing the P amyQ' promoter produced the greatest extracellular β-CGTase activity; 24.1 U/mL.
Mervi kärki hemsida

product | cost management | activity | sul | agribusiness | environmental cost fab | cgtase | fed-batch cultivation | biolector | dera | autodisplay | enbase 844

Cell growth and CGTase synthesis in SSC using SIFR as substrate After three rounds of mutagenesis the hydrolytic activity had increased 90-fold, reaching the highest hydrolytic activity ever reported for a CGTase. The single mutation with the largest effect (A230V) occurred in a residue not studied before. 2017-02-20 · α-CGTase activity. The α-CGTase cyclization activity was measured using an assay similar to that described above for β-CGTase activity. A 0.1 mL aliquot of appropriately diluted crude enzyme was added to 2 mL of preheated 2% (w/v) soluble starch dissolved in 25 mM phosphate buffer (pH 5.5).

A cyclic activity of accumulation and consumption of beta -CD and gamma -CD occurred during the bacterial growth. CGTase was more active when citrate buffer, pH 5.5 was used. No differences were found for production of gamma -CD with the use of commercial starch flour when compared with corn starch (p>0.05).

Optimum temperature for maximum CGTase activity was found to be 70 °C as shown in Fig. 6. At temperature higher than 70 °C, activity of CGTase declines sharply may be because the CGTase could be denatured above 70 °C. Relative activity also decreased by about 60% at 80 °C.

CGTase, was selected from B. cereus YUPP-10 by a constructed fos-mid library. We discovered that CGTase has antimicrobial activity and induces resistance. In addition, we have revealed the key do-mains responsible for its hydrolytic activity and resistance induction. Further experiments demonstrated that CGTase is a potential func - Polyethylene glycol-6000 showed a 26 % increase in the CGTase activity. The kinetic parameters Km and Vmax were 10 mg/ml and 146 µmol/mg min, respectively, for purified CGTase. CGTase can catalyse four reactions: cyclization, coupling, disproportionation, and hydrolysis (Li et al., 2014b), though the hydrolysis activity is relatively weak (Costa et al., 2009).