Chimeric alpha-amylase variants

Patent metadata

Field	Value
Publication number	US-9303254-B2
Application number	US-201314038405-A
Country	US
Kind code	B2
Filing date	Sep 26, 2013
Priority date	Apr 30, 2008
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Chimeric alpha-amylases having the characteristics of high thermostability and good performance in starch degradation, especially high-temperature liquefaction processes, are provided. The alpha-amylases are chimeras of AmyL and AmyS enzymes, and are useful in starch degradation processes. Methods of making the chimeric enzymes, and methods of using the chimeric alpha-amylases for liquefaction, cleaning starch residue from a surface, and treating woven material to remove coatings. Kits for practicing the methods are provided. Polynucleotides encoding the chimeric amylases, vectors, and expression hosts also are provided.

First claim

What is claimed is:

1. A chimeric polypeptide having at least about 95% sequence identity to SEQ ID NO:11, wherein said chimeric polypeptide has amylase catalytic activity and enhanced thermostability relative to a wild type AmyS amylase.

2. The chimeric polypeptide of claim 1 wherein the amylase catalytic activity is a retained amylase catalytic activity of at least 50% after incubation at 95° C. for 30 minutes.

3. The chimeric polypeptide of claim 2 that retains at least about 60% of its catalytic activity after incubation at 95° C. for 60 minutes.

4. The chimeric polypeptide of claim 3 which retains at least about 80% of its catalytic activity after incubation at 95° C. for 60 minutes.

5. A composition comprising the chimeric polypeptide of claim 1 .

6. The composition of claim 5 further comprising one or more additional polypeptides.

7. The composition of claim 6 , wherein the one or more additional polypeptides is an enzyme.

8. The composition of claim 5 that includes one or more detergents or cleaning agents.

9. The composition of claim 5 that is formulated for use in food or food processes.

10. A food-grade lyophilized composition comprising the composition of claim 5 .

11. A method of liquefying a starch slurry comprising:
making a slurry comprising a starch,
heating the slurry to an acceptable temperature for liquefaction,
adding to the slurry, a composition comprising the composition of claim 5 , and
incubating the slurry with the composition for a time and at a temperature sufficient to liquefy the starch slurry.

12. The method of claim 11 , wherein the addition of the composition
reduces the peak viscosity of the slurry as well as the addition of an AmyS amylase used in a comparable liquefaction, and
reduces the final viscosity of the slurry as well as the addition of an AmyL amylase used in a comparable liquefaction.

13. The method of claim 12 , wherein the temperature is at least about 80° C. to about 100° C.

14. The method of claim 11 , wherein the slurry comprises about 15-40% starch on a dry-weight basis.

15. The method of claim 14 , wherein the liquefaction is part of a fermentation.

16. The method of claim 15 , wherein the fermentation is used to produce a food product, a food additive, a fuel, or a fuel additive.

17. The method of claim 16 , wherein the fuel or fuel additive is an alcohol.

18. The method of claim 17 , wherein the alcohol is ethanol.

19. A method of cleaning a surface to remove starch residue comprising the steps of providing a surface that has starch residue to be removed, contacting the surface with a composition of claim 5 , for a time and at a temperature sufficient to result in removal of the starch residue.

20. The method of claim 19 , wherein the composition comprises one or more of a protease, a lipase, an additional amylase, or a combination thereof.

21. The method of claim 20 further comprising a step of rinsing or bulk removal of residue prior to the contacting step.

22. The method of claim 19 , wherein the temperature during the contacting step reaches at least 50-100° C.

23. A method of treating a woven material that has been previously subjected to contact with a coating comprising starch or a starch-derivative, the method comprising contacting the woven material with a solution comprising a composition according to claim 5 for a time and under conditions sufficient to substantially remove the coating from the woven material.

24. The method of claim 23 , wherein the woven material is a fabric.

25. The method of claim 23 , wherein the contacting step is performed at a pressure that is greater than ambient atmospheric pressure.

26. A kit for facilitating liquefaction of starch slurry, said kit comprising the chimeric polypeptide of claim 1 , and
instructions for use of the kit in the liquefaction of a starch slurry.

Assignees

• Danisco Us Inc

Inventors

• Power Scott D
• Shaw Andrew

Classifications

• C12N9/96 Primary

  Stabilising an enzyme by forming an adduct or a composition; Forming enzyme conjugates · CPC title

• A23L1/034

  Human Necessities · mapped topic

• C12N9/2417

  from microbiological source · CPC title

• Y02E50/17

  Cross-Sectional Technologies · mapped topic

• C11D3/38618

  Protease or amylase in liquid compositions only · CPC title