Purification and some properties of cyclomaltodextrin glucanotransferase from Bacillus circulans.

Abstract

Cyclomaltodextrin glucanotransferase was purified from B. circulans C31 through two successive steps of starch and Biogel column chromatography. The enzyme was purified up to 90fold with a 30% yield. Its molecular weight was around 103,000. The purified enzyme converted 28% of the soluble starch to /?-cyclodextrin at pH 7.0 and a substrate concentration of 5%. The optimum pH for the enzymewas found to be 5.5. The optimum temperature was 60°C. The enzyme was stable from pH 5.5~9.0 and up to 50°C. Cyclomaltodextrin glucanotransferase (EC 2.4.1.19, CGTase)*1 catalyzes the formation of cyclodextrins from starch and related carbohydrates such as amylose, amylopectin, glycogen and maltooligosaccharides.1* Certain species of Bacillus have been found to produce CGTases which may differ from one another in various properties and especially in the ratio of cyclodextrin products, a : /? : y formed.2~15) Although studies on CGTases from B. macerans and an alkalophilic Bacillus (ATCC 21783) have been by very extensive,2~4'10~13) investigations of those from other strains have not been reported much. As to B. circulans, only one study on CGTase was reported, by Okada and Kitahata.5) In our previous study,16) a Bacills species was selected for its high-CGTase producting ability. It closely resembled B. circulans as to

Efficient extracellular recombinant production and purification of a Bacillus cyclodextrin glucanotransferase in Escherichia coli

“…This low-cost and rapid method has previously been described for the purification of other CGTases [31, 32]. …”

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

“…Although B. circulans is a b-CD producer it also produces small amounts of a-CD and c-CD [10]. The present study investigated the formation of these CDs by TLC of the reaction products.…”

Optimization of cyclodextrin production from sago starch

“…Two hundred microliters of enzyme solution were incubated with 400 ll of 40 g l À1 amylose in 0.2 M phosphate buffer at 37°C for 3 h. A 500 ll aliquot of mixture was transferred to 500 ll of cold methanol (Larsen et al, 1998b;Pongsawasdi and Yagisawa, 1988). The b-CD formed in the reaction mixture was detected by high performance liquid chromatography (HPLC), as described in the next section.…”