Kao Corporation

Yasuhiro Hayashi

Katsuya Ozaki

Kazuaki Igarashi

Hiroshi Hagihara

Keiji Endo

Hiroyuki Araki

Kaori Kitayama

Susumu Ito

Yuji Hatada

Kaori Ikawa

The invention relates to mutant &#x3b1;-amylases that may be produced at high yield from recombinant microorganisms.

Highly productive &#x3b1;-amylases

The invention relates to a mutant &#x3b1;-amylase obtained by making replacement or deletion of at least one of amino acid residues such as the 167th Gln, 169th Tyr and 178th Ala in the amino acid sequence set forth in SEQ ID NO:1 in an &#x3b1;-amylase having said amino acid sequence, or an &#x3b1;-amylase having a homology of at least 70% to said amino acid sequence, a gene encoding the mutant &#x3b1;-amylase, a vector, transformed cells, a process for producing a mutant &#x3b1;-amylase, comprising culturing the transformed cells, and a detergent composition comprising the mutant &#x3b1;-amylase. The mutant &#x3b1;-amylase of the invention has excellent properties of high resistance to chelating agents, high specific activity in an alkaline region and excellent stability to heat, and is hence useful for detergents for automatic dish washer, laundry detergents and the like.

Mutant &#x3b1;-amylases

Liquefying alkaline amylases, each having residual activity not less than 70% when treated at pH 10 and 45&#xb0; C. for 30 minutes in the presence of 1 to 100 mM of EDTA or EGTA, are described. Also described are detergents comprising these amylases. In comparison with conventional amylases for detergents, the liquefying alkaline amylases of this invention have a high chelating-agent resisting performance.

Amylases

The invention relates to mutant &agr;-amylases that may be produced at high yield from recombinant microorganisms.

Highly productive alpha-amylases

The invention relates to a mutant &agr;-amylase having an amino acid sequence obtained by making deletion or replacement by another arbitrary amino acid residue of at least a methionine residue at the 202-position or a position homologous thereto among amino acid residues set forth in SEQ ID NO:1, which constitute a liquefying alkaline &agr;-amylase, a gene thereof, and a detergent composition comprising the mutant &agr;-amylase. The mutant &agr;-amylase has the optimum pH in an alkaline range, an excellent &agr;-amylase activity, and high and lasting resistance to oxidizing agents, and is hence particularly useful as a component of detergent compositions containing a bleaching agent and an oxidizing agent.

Mutant &agr;-amylases

Described are liquefying alkaline amylases each having residual activity not less than 70% when treated at pH 10 and 45&deg; C. for 30 minutes in the presence of 1 to 100 mM of EDTA or EGTA; and a detergent comprising the same. Compared with the conventional amylases for a detergent, they have high chelating-agent resisting performance.

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Tochigi, Japan

Yasuhiro Hayashi