title: Characterization of a thermostable levansucrase from Bacillus sp. TH4-2 capable of producing high molecular weight levan at high temperature.
abstract: A thermoactive and thermostable levansucrase was purified from a newly isolated thermophilic Bacillus sp. from Thailand soil. The purification was achieved by alcohol precipitation, DEAE-Cellulose and gel filtration chromatographies. The enzyme was purified to homogeneity as determined by SDS-PAGE, and had a molecular mass of 56 kDa. This levansucrase has some interesting characteristics regarding its optimum temperature and heat stability. The optimum temperature and pH were 60 degrees C and 6.0, respectively. The enzyme was completely stable after treatment at 50 degrees C for more than 1 h, and its activity increased four folds in the presence of 5 mM Fe(2+). The optimum temperature for levan production was 50 degrees C. Contrary to other levansucrases, the one presented in this study is able to produce high molecular weight levan at 50 degrees C.
authors.affiliation: Laboratory of Enzyme Chemistry, Faculty of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. youseff76@hotmail.com
authors.forename: Youssef
authors.initials: Y
authors.lastname: Ben Ammar
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Matsubara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ito
authors.forename: Masaru
authors.initials: M
authors.lastname: Iizuka
authors.forename: Tipaporn
authors.initials: T
authors.lastname: Limpaseni
authors.forename: Piamsook
authors.initials: P
authors.lastname: Pongsawasdi
authors.forename: Noshi
authors.initials: N
authors.lastname: Minamiura
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D004795:Enzyme Stability; D005630:Fructans / Q000096:biosynthesis* / Q000302:isolation & purification*; D006602:Hexosyltransferases / Q000302:isolation & purification* / Q000378:metabolism*; D008970:Molecular Weight; D012680:Sensitivity and Specificity; D013395:Sucrose / Q000378:metabolism*; D013696:Temperature
chemical_list: D005630:Fructans; D013395:Sucrose; D006602:Hexosyltransferases; C021513:levansucrase