Tuning a Dishwasher Enzyme to Chew Starch Harder Amylase Variants With a Wash Score

This application covers engineered versions of a starch-digesting enzyme, alpha-amylase, built to clean better in laundry and dishwasher detergents. Claim 1 defines the variants by a long list of amino acid positions that may be changed in a parent enzyme, plus a sequence identity window of at least 59 per cent but less than 100 per cent to the parent sequences. It was filed by Novozymes A/S, the Danish industrial enzyme company, and names six inventors. The application is a divisional of Australian application 2020242303.

The Problem

Alpha-amylases break the internal bonds in starch, and the specification notes they have long been used in laundry because they help remove starch-based stains. They matter in other industries too, including starch liquefaction, textile desizing and alcohol production. Within detergents, though, the pressure has been on lowering wash temperatures to cut energy use, and an enzyme that works well in a warm industrial process may do less in a cool domestic wash.

The specification states the aim plainly: to provide alpha-amylases with improved wash performance, especially for automatic washing machines and dishwashers. Dried-on starch, from pasta, rice, porridge or potato on plates, is a hard soil to remove. A detergent that depends on an enzyme to do that has to keep the enzyme working alongside bleach, builders and surfactants, which is a demanding chemical setting for a protein.

The specification does not claim a single miracle mutation. It describes a search: a parent enzyme, a library of variants made by changing it at many positions, and a standard way of scoring each variant against the parent.

What This Invention Does

Claim 1 is an alpha-amylase variant of a parent alpha-amylase polypeptide that carries a modification (a substitution, insertion or deletion) at one or more of more than a hundred listed positions, numbered using SEQ ID NO: 1. The variant must have at least 59 per cent but less than 100 per cent sequence identity to the polypeptides of SEQ ID NOs: 1 to 17, and it must still have alpha-amylase activity.

Claim 2 narrows this. The positions are given with their original residues (for example H1, G7, N195, V264, Y267, Q365), and the variant must have an Improvement Factor (IF) above 1.0 for wash performance compared with the parent of SEQ ID NO: 1 or SEQ ID NO: 2. Claim 3 covers variants with deletions at two or more of R181, G182, D183 and G184. Claims 6 and 7 list specific named variants, from single changes such as A60T, Q169E and W48Y to combinations such as N195F plus Q365S and V264I plus Y267F plus Q365K. Claims 8 to 10 cover detergent compositions containing a variant, claims 11 to 14 cover use, soil removal, dishwashing and laundering methods, and claim 15 covers a method of improving the wash performance of a parent enzyme.

The specification defines wash performance through the IF, and calls performance improved if the IF is at least 1.1. The variants were built from a parent of SEQ ID NO: 2, an enzyme the specification places in glycoside hydrolase family GH13, subfamily 5. In the first screen (Example 3), a rice starch swatch in a microtitre plate was washed with Model A detergent at 3.45 g/l in water of 21 degrees dH hardness, and the starch released was measured as glucose. In the second (Example 5), variants were tested in a full-size Miele GSL2 dishwasher at 40 and 45 degrees C on starch-stained melamine tiles, with 50 g of ballast soil and bleach-containing model detergent.

The reported scores are modest for single changes and larger for combinations. Single changes in the Example 3 table score roughly 1.1 to 1.4. Pairs do better: N195F plus Q365C scores 2.6, N195F plus Q365S 2.1, and R127L plus Q365S 2.0. The specification gives preferred IF levels up to at least 4.0 in some dependent embodiments, but the tables in the examples reach the figures above.

Key Features

• A scoring system built into the claim. The Improvement Factor compares each variant with the parent under the same conditions, so “better” is measured, not asserted.
• Hundreds of possible edits, one family. Claim 1 lists more than a hundred positions, and claims 6 and 7 name specific substitutions and combinations, so the application covers a family of variants and not a single enzyme.
• Deletions in a four-residue loop. Claim 3 and claim 15 single out deletions or substitutions at R181, G182, D183 and G184 as a route to better wash performance.
• Tested in dishwasher conditions. Examples cover Model A laundry detergent in the plate assay and full-scale automatic dishwashing at 40 and 45 degrees C with a bleach-containing detergent.
• Covers the gene as well as the protein. The specification also describes polynucleotides encoding the variants, vectors, host cells and methods of production, although the claims in this divisional concentrate on the variants, compositions and wash methods.
• Applies to laundry and dishwashing. Claims 12 to 14 cover removing soils from fabric or hard surfaces, dishwashing in an automatic machine, and laundering in an automatic machine.

Who Is Behind It

The applicant is Novozymes A/S, the Danish industrial biotechnology company based in Bagsvaerd near Copenhagen. It was founded in 2000 as a spin-out from Novo Nordisk, and it merged with Chr. Hansen in January 2024 to form Novonesis. The company’s own site, Novonesis, still carries the copyright line “Novozymes A/S, part of Novonesis Group” and lists household care as one of its six biosolution categories. Enzymes for detergents are one of the company’s oldest markets, and its Lipolase fat-splitting enzyme, introduced in the late 1980s, is described as the world’s first made with genetically engineered microorganisms.

The six inventors named are Carsten Andersen, Sofia Arnehed, Lars Lehmann Hylling Christensen, Ali Fallah-Araghi, Markus Klinger and Anders Gunnar Sandstrom. The specification says nothing about their employers.

On priority, the specification is explicit. It states that it is a divisional of Australian application 2020242303, filed 20 March 2020, is related to PCT/EP2020/057818, and claims priority from European application 19164228.9 filed 21 March 2019. The priority country is therefore the European Patent Office. The specification also notes that the sequence listing was filed in ST.26 XML format on 10 March 2026.

Why It Matters

Enzymes in detergents are a quiet part of household chemistry. Ever since manufacturers started adding them, the work has been to get more cleaning from the same dose, or the same cleaning at a lower temperature. A better alpha-amylase lets a dishwasher tablet or laundry powder deal with starch stains using less enzyme or a shorter, cooler cycle.

The method on show is also worth noting: protein engineering by making many small changes, measuring each, and combining the winners. Protecting the whole family of variants, and the method of improving a parent, is a way to cover the result of a large screening programme rather than one lucky enzyme. The specification supports the claim with plate and dishwasher data, but reports its numbers as ratios to a parent, so a reader cannot tell absolute stain removal from it.

Related Concepts

• Alpha-amylase – the starch-cleaving enzyme family that the variants are built from.
• Protein engineering – the practice of changing amino acids in a protein to improve a property such as wash performance.
• Site-directed mutagenesis – the technique of introducing planned amino acid changes at chosen positions.
• Glycoside hydrolase – the enzyme class, here family GH13, to which the parent amylase belongs.
• Dishwasher detergent – the cleaning product in which the improved enzyme is meant to work.

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AU 2026202266 was published in the Australian Official Journal of Patents on 16 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.