Maltotriose, from starch

Naltotriose-producing Amylases. Amylases that produce maltotriose from starch as the major end-product have not been reported commonly. Indeed the only enzyme in this category is the enzyme from Streptomyces griseus (24). This is an exo-acting enzyme that hydrolyses its substrate from the non-reducing end to produce maltotriose in the a-configuration (31). The enzyme hydrolyses short chain amylose completely but the extent of hydrolysis with starch and waxy maize starch as substrate is 55 and 51% respectively. The optimum pH for activity is 5.6-6.0 and the enzyme is stable up to 40 C but rapidly denatured at temperatures above 45 C. 

In 1978, Wako et al49 described an enzyme from Streptomyces griseus that produced primarily maltotriose from the non-reducing ends of starch chains. Amylose... 

Maltotriose, III, 254 from arrow-root Starch, III, 274 from a-dextrins, III, 277 from soluble starch, III, 272 from starch, III, 288, 291, 308 Mandelic acid, effect on conductivity of boric acid, IV, 195... 

Pullulan is a glucan of (1 6)-a-D-linked maltotriose residues produced by Aureobasidium pullulans from starch or sucrose feedstockJ It is well soluble in aqueous medium and forms films that possess thermal stability and are antistatic and elastic. Pullulan has adhesive properties and is directly compressible under heat with moisture. The polysaccharide is produced on an industrial scale and is used for multiple applications, including food, pharmaceuticals, and cosmetics. It has recently been classified as GRAS by the U.S. FDA. 

We dived into Challenger Deep at the depth of 10,897m on March 2 1996 and have collected the mud samples. We have isolated strain MS300 which produces exo-maltotetraohydrase (amylase300) from the mud sample. The amylase300 predominantly maltotetraose from starch. This amylase300 to be very unique. Because, the exo-maltotetraohydrolase of Pseudomonas stutzeri strains had been reported but this enzyme produces glucose maltose and maltotriose besides maltotetraose from starch. We can expect the deep sea environment as the resource of novel microbial biocatalysts. 

A strain of Bacillus cereus synthesizes a pullulanase and a -amylase, which together convert starch into maltose in high yield. The homogeneous pullulanase was obtained by fractional precipitation, adsorption onto starch and Celite, and gel filtration. The purified enzyme (pH optimum 6.0—6.5, mol. wt. 1.10 0.20 X 10 ) released maltose, maltotriose, and maltotetraose from -limit dextrin and maltotriose from pullulan, but it did not release amylose-like substances from amylopectin. The enzymic activity was inhibited by mercuric chloride and 4-chloromercuribenzoate, although the activity in the latter instance could be restored by cysteine. 

The transglycosylation reactions catalysed by cyclodextrin D-glucano-transferases from B. megaterium and B. macerans have been shown to differ towards such acceptors as D-glucose, maltose, maltotriose, and sucrose. It was suggested that cyclodextrin D-glucanotransferase may transfer D-glucosyl residues from starch, as well as from cyclodextrins, to an acceptor. 

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