title: Improved thermostable α-amylase activity of Bacillus amyloliquefaciens by low-energy ion implantation.
abstract: Thermostable  α-amylase is of  great importance in the starch fermentation industry; it is extensively used in the  manufacture of beverages, baby foods, medicines, and pharmaceuticals. Bacillus amyloliquefaciens produces thermostable α-amylase; however,  production of thermostable α-amylase  is limited. Ion-beam implantation is an effective method for mutation breeding  in microbes. We conducted ion-beam implantation experiments using two different  ions, Ar(+) and N(+), to  determine the survival rate of and dose effect on a high α-amylase activity strain of B.  amyloliquefaciens that had been isolated from soil samples. N(+) implantation  resulted in a higher survival rate than Ar(+) implantation.  The optimum implantation dose was 2.08 × 10(15) ions/cm(2). Under  this implantation condition, we obtained a thermally and genetically stable  mutant α-amylase  strain (RL-1) with high enzyme activity for degrading α-amylase. Compared to the parental  strain (RL), the RL-1 strain had a 57.1% increase in α-amylase activity. We conclude that  ion implantation in B. amyloliquefaciens can produce strains with  increased production of thermostable α-amylase.
authors.affiliation: Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Li
authors.forename: J L
authors.initials: JL
authors.lastname: Zhang
authors.forename: S W
authors.initials: SW
authors.lastname: Zhu
mesh_terms: D001128:Argon / Q000737:chemistry; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004795:Enzyme Stability; D006358:Hot Temperature; D007477:Ions / Q000737:chemistry; D009154:Mutation; D009584:Nitrogen / Q000737:chemistry; D000516:alpha-Amylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D007477:Ions; D001128:Argon; D000516:alpha-Amylases; D009584:Nitrogen