title: Purification and characterization of a maltooligosaccharide-forming amylase that improves product selectivity in water-miscible organic solvents, from dimethylsulfoxide-tolerant Brachybacterium sp. strain LB25.
abstract: A bacterium that secretes maltooligosaccharide-forming amylase in a medium containing 12.5% (vol/vol) dimethylsulfoxide (DMSO) was isolated and identified as Brachybacterium sp. strain LB25. The amylase of the strain was purified from the culture supernatant, and its molecular mass was 60 kDa. The enzyme was stable at pH 7.0-8.5 and active at pH 6.0-7.5. The optimum temperature at pH 7.0 was 35 degrees C in the presence of 5 mM CaCl(2). The enzyme hydrolyzed starch to produce maltotriose primarily. The enzyme was active in the presence of various organic solvents. Its yield and product selectivity of maltooligosaccharides in the presence of DMSO or ethanol were compared with those of the industrial maltotriose-forming amylase from Microbacterium imperiale. Both enzymes improved the production selectivity of maltotriose by the addition of DMSO or ethanol. However, the total maltooligosaccharide yield in the presence of the solvents was higher for LB25 amylase than for M. imperiale amylase.
authors.affiliation: Department of Life Science,Toyo University, 1-1-1 Izumino, Itakura-machi, Gunma, Japan. doukyu@itakura.toyo.ac.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Doukyu
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamagishi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kuwahara
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ogino
authors.forename: Noritake
authors.initials: N
authors.lastname: Furuki
mesh_terms: D000192:Actinomycetales / Q000145:classification / Q000187:drug effects / Q000201:enzymology*; D000681:Amylases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002122:Calcium Chloride / Q000737:chemistry; D016895:Culture Media, Serum-Free / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry* / Q000494:pharmacology; D004789:Enzyme Activation; D004795:Enzyme Stability; D000431:Ethanol / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008970:Molecular Weight; D009161:Mycobacterium / Q000201:enzymology; D009844:Oligosaccharides / Q000378:metabolism*; D012988:Soil Microbiology; D012995:Solubility; D012997:Solvents / Q000737:chemistry* / Q000494:pharmacology; D013213:Starch / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D014312:Trisaccharides / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D016895:Culture Media, Serum-Free; D009844:Oligosaccharides; D012997:Solvents; D014312:Trisaccharides; C021705:maltooligosaccharides; D000431:Ethanol; C008317:maltotriose; D013213:Starch; D000681:Amylases; D002122:Calcium Chloride; D004121:Dimethyl Sulfoxide