Characterization of a thermostable levansucrase from Bacillus sp. TH4-2 capable of producing high molecular weight levan at high temperature.
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.
Ben Ammar
Youssef
Y
Laboratory of Enzyme Chemistry, Faculty of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. youseff76@hotmail.com
Matsubara
Takayoshi
T
Ito
Kazuo
K
Iizuka
Masaru
M
Limpaseni
Tipaporn
T
Pongsawasdi
Piamsook
P
Minamiura
Noshi
N
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
D005630:Fructans; D013395:Sucrose; D006602:Hexosyltransferases; C021513:levansucrase