The invention relates to a novel Termamyl-like alpha-amylase, and Termamyl-like alpha-amylases comprising mutations in two, three, four, five or six regions/positions. The variants have increased thermostability at acidic pH and/or at low Ca
2+
concentrations (relative to the parent). The invention also relates to a DNA construct comprising a DNA sequence encoding an alpha-amylase variant of the invention, a recombinant expression vector which carries a DNA construct of the invention, a cell which is transformed with a DNA construct of the invention, the use of an alpha-amylase variant of the invention for washing and/or dishwashing, textile desizing, starch liquefaction, a detergent additive comprising an alpha-amylase variant of the invention, a manual or automatic dishwashing detergent composition comprising an alpha-amylase variant of the invention, a method for generating a variant of a parent Termamyl-like alpha-amylase, which variant exhibits increased thermostability at acidic pH and/or at low Ca
2+
concentrations (relative to the parent).
本发明涉及一种新型的Termamyl类α
淀粉酶,以及包含在两个、三个、四个、五个或六个区域/位置中发生突变的Termamyl类α
淀粉酶。这些变异体在酸性pH和/或低Ca2+浓度下(相对于父代)具有增强的热稳定性。本发明还涉及一种DNA构建物,该构建物包括编码本发明α
淀粉酶变异体的DNA序列,携带本发明构建物的
重组表达载体,转化有本发明构建物的细胞,使用本发明α
淀粉酶变异体进行洗涤和/或洗碗、纺织品脱浆、淀粉液化,以及包含本发明α
淀粉酶变异体的洗涤剂添加剂、手动或自动洗碗剂组合物,以及一种用于生成父Termamyl类α
淀粉酶变异体的方法,该变异体在酸性pH和/或低Ca2+浓度下(相对于父代)具有增强的热稳定性。