Abstract: To provide a method for preparing a highly diverse mutation library pool at a low price easily. A method for preparing a mutation library pool, comprising the following steps (a) to (c): (a) subjecting a template DNA and each of a plurality of mutagenic primer pairs to DNA synthesis reaction with a DNA polymerase to acquire DNA fragments having 5?-protruding ends, wherein each of the mutagenic primer pairs anneals to the template DNA, primers of each primer pair have regions complementary to each other, and at least one of the primers comprises a mutagenic site; (b) allowing a DNA ligase to act on the DNA fragments obtained in step (a); and (c) transforming host cells with the DNAs obtained in step (b).

Abstract: Provided are a rigid surface treatment agent capable of imparting an antibacterial property to a rigid surface, and a method for treating a rigid surface using the rigid surface treatment agent. The rigid surface treatment agent comprises, as an active component, a polypeptide which consists of an amino acid sequence of SEQ ID NO: 2, or a polypeptide which consists of an amino acid sequence having an identity of at least 80% with the amino acid sequence of SEQ ID NO: 2, and has activity of degrading a glycine-glycine bond in a peptide sequence.

Abstract: Provided is an ?-amylase which exhibits high amylolytic activity at low temperatures. An ?-amylase mutant, wherein an amino acid residue at a position of the following (a) and (b); (c); or (a), (b), and (c), in the amino acid sequence of SEQ ID NO: 2 or an amino acid sequence having at least 90% identity thereto is substituted with another amino acid residue: (a) position 303 of the amino acid sequence of SEQ ID NO: 2 or a position corresponding thereto; (b) one or more positions selected from the group consisting of position 295 and position 296 of the amino acid sequence of SEQ ID NO: 2 and positions corresponding thereto; or (c) position 331 of the amino acid sequence of SEQ ID NO: 2 or a position corresponding thereto.

Abstract: Provided are a leather improving agent which exhibits the effect of suppressing contraction of hide to enlarge the area; and a method for treating leather using the leather improving agent. The leather improving agent comprises an M23A subfamily protease as an active ingredient.

Abstract: Provided are a polypeptide having a glycine-glycine bond-degrading activity and an improved microbicidal activity, and a method for using the same.

Abstract: Provided is a detergent having a high detergency against corneum-derived stains and a method for evaluating the ability of an enzyme to degrade corneum-derived stains. The detergent a M23A subfamily protease as an active ingredient. The method for evaluating the ability of the enzyme to degrade corneum-derived stains comprises obtaining the degrading activities of the test enzyme on a reference peptide and one or more substrate peptides and evaluating the ability of the test enzyme to degrade corneum-derived stains based on the degrading activities of the test enzyme on the reference peptide and the substrate peptide, wherein the reference peptide is GGGGG or GGGG, the one or more substrate peptides are selected from the group consisting of GGGXG, GXGGG, GGXG, and GXGG, and X is any amino acid residue other than glycine.

Abstract: Provided is an ?-amylase which can function at low temperatures while maintaining or enhancing stability and/or cleaning performance. An ?-amylase mutant, which is a mutant of a parent ?-amylase, the ?-amylase mutant comprising one or more modifications to amino acid residues at positions corresponding to positions G5, S38, T49, Q96, N126, T129, G140, F153, Q167, G179, W186, E187, N192, M199, Y200, L203, Y205, D206, R211, K215, H240, S241, Y242, G244, E257, F259, K278, H283, S284, A288, H295, Y296, N303, T320, S331, L348, Y360, W408, L429, V430, G433, A434, W439, N471, G476, and G477 in the amino acid sequence of SEQ ID NO: 2, the parent ?-amylase or ?-amylase mutant having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 4.

Abstract: Provided is a cleaning composition containing ?-amylase which exhibits high specific activity at low temperatures. The cleaning composition comprises one or more proteins selected from the group consisting of the following (A), (B), (C), and (D): (A) a protein consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 2, and having ?-amylase activity; (B) a protein consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 4, and having ?-amylase activity; (C) a protein consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 6, and having ?-amylase activity; and (D) a protein consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 8, and having ?-amylase activity.

Abstract: Provided is a method for efficiently producing an M23A family protease. The method for producing an M23A family protease includes culturing bacteria of the genus Bacillus having a polynucleotide encoding a proprotein of the M23A family protease introduced thereinto to produce a mature form of the M23A family protease extracellularly from the bacteria of the genus Bacillus.

Abstract: Provided is a method for efficiently producing an M23A family protease. The method for producing an M23A family protease includes culturing bacteria of the genus Bacillus having a polynucleotide encoding a proprotein of the M23A family protease introduced thereinto to produce a mature form of the M23A family protease extracellularly from the bacteria of the genus Bacillus.

Abstract: The present invention provides a detergent having a high detergency against corneum-derived stains, a method for evaluating the ability of an enzyme or a composition comprising the enzyme to degrade corneum-derived stains. A detergent comprising an M23A subfamily protease as an active ingredient.