CA2320759A1 - Alkaline bacillus amylase - Google Patents

Abstract

The present invention relates to amylases having improved washing performance in an alkaline detergent solution at low temperature. More specifically, the present invention provides novel a-amylases from Bacillus sp. with improved performance in alkaline solutions, especially in alkaline detergent solutions at pH around 9-11.

Description

ALKALINE BACILLUS AMYLASE
FIELD OF INVENTION
The present invention relates to amylases having improved washing performance in an alkaline detergent solution at low s temperature.
BACKGROUND OF THE INVENTION
For a number of years a-amylase enzymes have been used for a variety of different purposes, the most important of which are starch liquefaction, textile desizing, starch modification in io the paper and pulp industry, and for brewing and baking. A
further use of a-amylases, which is becoming increasingly impor-tant is the removal of starchy stains during washing with a detergent at alkaline pH.
Examples of commercial a-amylase products are Termamyl°, i5 BAN° and Fungamyl°, all available from Novo Nordisk A/S, Denmark. These and similar products from other commercial sour ces have an acidic to a neutral pH optimum, typically in the range of from pH 5 to pH 7.5, and they do not display optimal activity in detergent solutions at alkaline pH.
2o WO 95/26397 discloses an a-amylase from a Bacillus strain which has optimum activity at pH 8. WO 96/23873 describes variants of Bacillus amylases with improved performance under washing conditions.
US 5,147,796 describes an alkaline pullulanase having is alpha-amylase activity. Fig. 2b of the document shows optimum amylase activity at pH 8-8.5.
M. Takagi et al., J. Ferment. Bioeng., vol 81, No. 6, 557-559 (1996) describe an alkaliphilic alpha-amylase-pullulanase from Bacillus sp. The enzyme has optimum amylase activity at pH
30 9, but the activity drops rapidly at higher pH, and the activity at pH 10 is lower than at pH 7.
It is an object of the present invention to provide novel a-amylases with improved performance in alkaline solutions, especially in alkaline detergent solutions at pH around 9-11.

WO 99/.12567 PCT/DK99/00066 SZJMMARY OF THE INVENTION
~r:e present invention provides alpha-amylase whic:~. is:
a) a polypeptide produced by Bacillus sp. NCINB 46916, or s b) a polypeptide having an amino acid sequence as shown in positions 32-532 of SEQ ID NO: 2, or c) - a polypeptide encoded by the alpha-amylase encoding part of the DNA sequence cloned into a plasmid present in Escherichia coli DSM 12662, or io d) an analogue of the polypeptide defined in (a) or (b) which:
i) is at least 60 % homologous with said polypeptide, or ii) is derived from said polypeptide by is substitution, deletion and/or insertion of one or several amino acids.
In another aspect, the invention provides an a-amylase having one or more of the following characteristics:
~an activity at pH 10.5 which is at least two times Zo higher than the activity at pH 7.3 when measured at 37°C.
~an activity at pH 9.5 which is at least 4 times higher than the activity at pH 7.3 when measured at 37°C.
~an optimum pH of about 9.5 when measured at 37°C.
~a thermostability such that it retains more than 90 % of Zs its activity after 20 minutes incubation at 25°C in a solution of 3 g/1 of a test detergent containing 20% STPP, 25% Na2S04, 15% Na2C03, 20% LAS, 5% C12-C15 alcohol ethoxylate, 5%
Na2Si205, 0.3% NaCl at pH 10.5 and 6 degrees German hardness, and retains less than 90 % of its activity after 20 minutes 3o incubation at 30°C in the same solution.
~a molecular weight of about 55 kDa as determined by SDS-PAGE.
~an iso-electric point of about S as determined by isoelectric focusing.
as The invention also provides an isolated DNA sequence which encodes an alpha-amylase, wherein the alpha-amylase is that described above, or wherein the DNA sequence comprises:

V1'O 99/42567 PCTIDK99/00066 a) the DNA sequence showy. in positions 94-1596 of SEQ ID
NO: ', or b) an analogue of the DNA sequence defined in a) which i) is at least 60 % homologous with said DNA
= sequence, or ii) hybridizes with said DNA sequence at least 55°C.
Other aspects of the invention provide a recombinant expression vector comprising the DNA sequence, and a cell transformed with the Dh'~ sequence or the recombinant expression io vector. .
The invention also provides a method for producing an alpha-amylase by cultivating the cell and a detergent composition comprising said alpha-amylase.
BRIEF DESCRIPTION OF DRAWINGS
is The present invention is further illustrated with reference to the accompanying drawings, in which:
Fig. 1 shows a pH activity profile of the amylase from NCIMB 40916 compared to two prior-art amylases (SP722 and Termamyl).
zo Fig. 2 shows a temperature activity profile of the amylase from NCIMB 40916.
Fig. 3 shows the stability of the amylase from NCIMB
40916 after incubation at various temperatures.
Fig. 4 shows the cloning vector pSJ1678 described in ~s Example 1.
Figs. 5 and 6 show results of washing tests described in Example 4.
DETAILED DESCRIPTION OF THE INVENTION
Microbial source 3o The alpha-amylase of the invention may be derived from a strain of Bacillus. A preferred strain is Bacillus sp. NCIMB
40916. This strain was deposited on 28 January 1998 by the inventors under the terms of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes ef Patent Procedure at the National Collections o Industrial and Marine Bacteria Limited (NCIMB), 23 St. Machar Drive, Aberdeen AB2 1RY, Scotland, United Kingdom. A Escheri-chia coli strain termed JA388 containing the alpha amylase gene s cloned in plasmid nJA388 has also been deposited on 3 February 1999 under the terms of the Budapest Treaty with the Deutshe Sammmlung von Microorganismen and Zellkulturen GmbH (DSMZ), Mascheroder Weg 1b, D-38124 Braunschweig DE, and given the accession number DSM 12662.
io Production of alpha-amylase The alpha-amylase of the invention can be produced by cultivating a suitable amylase-producing strain of Bacillus or the transformed host cell of the invention in a suitable nu trient medium, and recovering the alpha-amylase from the cul i5 ture medium.
The medium used to cultivate the cells may be any conven-tional medium suitable for growing the host cell in question and obtaining expression of the a-amylase of the invention.
Suitable media are available from commercial suppliers o~ :y Zo be prepared according to published recipes (e.g. as desc~ d in catalogues of the American Type Culture Collection).
The a-amylase secreted from the host cells may ~n-veniently be recovered from the culture medium by well-known procedures, including separating the cells from the medium by is centrifugation or filtration, and precipitating proteinaceous components of the medium by means of a salt such as ammonium sulphate, followed by the use of chromatographic procedures such as ion exchange chromatography, affinity chromatography, or the like.
3o Properties of alpha-amylase A preferred alpha-amylase is derived from Bacillus sp.
NCIMB 40916. It can be produced as described in the examples.
The amino acid sequence of the amylase and of the DNA encoding it are shown in SEQ ID N0: 1 and 2. The following characteristics were found for an amylase of the invention (purified alpha-amylase from NCIMB 40916):
A molecular weight of approximately 55 kDa as determined by SDS-PAGE using a Novex, 4-25% gradient gel.
s A pI of approximately 5 was determined by isoelectric focusing (Ampholine PAG, pH 3.5-9.5).
A pH-activity curve is shown in Fig. 1, taking the activity at pH 7.3 as 100%. It was determined using the Phadebas assay using 50 mM Britten-Robinson buffer adjusted to io various pH-values. For reference, the pH profiles of two prior-art Bacillus amylases (Termamyl derived from B. licheniformis and SP722 produced according to WO 95/26397) were measured under the same conditions are also shown in Figure 1. Figure 1 shows that the amylase of the invention has about 10 times is higher activity than the two prior-art amylases at pH 9.5. Fig.
1 also shows that the optimum activity is about pH 9.5.
A temperature-activity curve was measured using the Phadebas assay at various temperatures with 50 mM Britten-Robinson buffer adjusted to pH 9.5. The results are shown in zo Fig. 2. It is seen from Fig. 2 that the amylase of the invention has optimum activity at about 55°C.
Stability of the amylase was measured at pH 10.5 (50 mM
CAPS) at 22, 37, 45, 55 and 65 °C after 30 minutes incubation.
The enzyme was diluted to 40 NU/ml in buffer and 25 microlitre zs sample was incubated at the respective temperatures. After 30 minutes, the samples was chilled on ice and residual activity was determined. A stability profile of the amylase of the invention and a prior-art amylase (SP722) is shown in Figure 3.
Stability was tested by incubating 40 NU/ml of amylase in ao a solution of 3 g/1 of the A/P model detergent described above, at pH 10.5 and 6°dH (German hardness, Ca:Mg 2:1). After the incubation, the residual activity was measured by Phadebas at pH 7.3. The results were 95 % residual activity after incubation at 25°C, and 87 % at 30°C.

Homology of polypeptide and DNA sequence The amino acid sequence hcmology may be determined as the degree of identity between the two sequences indicating a derivation of the first sequence from the second. The homology s may suitably be determined by means of computer programs known in the art. Thus, FASTA provided in GCG version 8 (Needleman, S.B. and Wunsch, C.D., (1970), Journal of Molecular Biology, 48, 443-453) may be used with the following settings: Scoring matrix: GenRunData:blosum50.cmp, Variable pamfactor used Gap io creation penalty: 12, Gap extension penalty: 2. Alternatively, Gap from GCG version 9 may be used with a translated version 8 peptide scoring matrix, a gap creation penalty of 30, a gap extension penalty of 1 using ntol's matrix (http://plasmid/-bioweb/matrix/) without end gap penalty.
is The amino acid sequence exhibits a degree of identity preferably of at least 60%, preferably at least 70%, more preferably at Least 80%, especially at least 90% or at least 95%, with the amino acid sequence shown in positions 32-532 of SEQ ID NO: 2.
zo The DNA sequence homology may be determined as the degree of identity between the two sequences indicating a derivation of the first sequence from the second. The homology may suitably be determined by means of computer programs known in the art such as GAP provided in the GCG program package is (described above). Thus, Gap GCGv8 may be used with the fol-lowing default parameters: GAP creation penalty of 5.0 and GAP
extension penalty of 0.3, default scoring matrix . GAP uses the method of Needleman/Wunsch/Sellers to make alignments.
The DNA construct of the present invention comprises a ao DNA sequence exhibiting a degree of identity preferably of at least 60%, preferably at least 70%, more preferably at least 80%, especially at least 90% or at least 95%, with the nucleic acid sequence shown in positions 94-1596 of SEQ ID NO: 1.
A homology search of known sequences showed homologies 3s for the sequences of the invention with a number of Bacillus amylases in the range 31-34 % on amino acid basis and 46-48 %
on DNA basis, determined as described above.

Hybridization The hybridization is used to indicate that a given DNA
sequence is analogous to a nucleotide probe corresponding to SEQ ID N0: 1. The hybridization conditions are described in s detail below.
Suitable conditions for determining hybridization between a nucleotide probe and a homologous DNA or RNA sequence involves presoaking of the filter containing the DNA fragments or RNA to hybridize in 5 x SSC (standard saline citrate) for 10 io min, and prehybridization of the filter in a solution of 5 x SSC (Sambrook et al. 1989), 5 x Denhardt's solution (Sambrook et al. 1989), 0.5 % SDS and 100 ~Cg/ml of denatured sonicated salmon sperm DNA (Sambrook et al. 1989), followed by hybridization in the same solution containing a random-primed is (Feinberg, A. P. and Vogelstein, B. (1983) Anal. Biochem.
132:6-13), 'ZP-dCTP-labeled (specific activity > 1 x 10" cpm/ug probe for 12 hours at approx. 45°C. The filter is then washed two times for 30 minutes in 2 x SSC, 0.5 % SDS at a temperature of at least 55°C, more preferably at least 60°C, more so preferably at least 65°C, even more preferably at least 70°C, especially at least 75°C.
Molecules to which the oligonucleotide probe hybridizes under these conditions are detected using a x-ray film.
Recombinant expression vector zs The expression vector of the invention typically includes control sequences encoding a promoter, operator, ribosome binding site, translation initiation signal, and, optionally, a repressor gene or various activator genes.
The recombinant expression vector carrying the DNA
3o sequence encoding the a-amylase of the invention may be any vector which may conveniently be subjected to recombinant DNA
procedures, and the choice of vector will often depend on the host cell into which it is to be introduced. Thus, the vector may be an autonomously replicating vector, i.e. a vector which 35 exists as an extrachromosomal entity, the replication of which is independent of chromosomal replication, e.g. a plasmid, a bacteriophage or an extrachromosomal element, minichromosome or an artificial chromosome. Alternatively, the vector may be one which, when introduced into a host cell, is integrated into the host cell genome and replicated together with the chromosomes) into which it has been integrated.
In the vector, the DNA sequence should be operably ' connected to a suitable promoter sequence. The promoter may be any DNA sequence which shows transcriptional activity in the host cell of choice and may be derived from genes encoding pro o teins either homologous or heterologous to the host cell.
Examples of suitable promoters for directing the transcription of the DNA sequence encoding an a-amylase of the invention, especially in a bacterial host, are the promoter of the Iac operon of E.coli, the Streptomyces coelicolor agarase gene dagA
is promoters, the promoters of the Bacillus licheniformis a-amylase gene (amyl), the promoters of the Bacillus stearothermophilus maltogenic amylase gene (amyM), the promo-ters of the Bacillus Amyloliquefaciens a-amylase (amyQ), the promoters of the Bacillus subtilis xylA and xylB genes etc. For zo transcription in a fungal host, examples of useful promoters are those derived from the gene encoding A. oryzae TAKA
amylase, Rhizomucor miehei aspartic proteinase, A. niger neu-tral a-amylase, A. niger acid stable a-amylase, A. niger glu-coamylase, Rhizomucor miehei lipase, A. oryzae alkaline zs protease, A. oryzae triose phosphate isomerase or A. nidulans acetamidase.
The expression vector of the invention may also comprise a suitable transcription terminator and, in eukaryotes, poly-adenylation sequences operably connected to the DNA sequence 3o encoding the a-amylase of the invention. Termination and poly-adenylation sequences may suitably be derived from the same sources as the promoter. -The vector may further comprise a DNA sequence enabling the vector to replicate in the host cell in question. Examples 35 Of such sequences are the origins of replication of plasmids pUCl9, pACYC177, pUB110, pE194, pAMBl and pIJ702.

The vector may also comprise a selectable marker, e.g. a gene the product of which complements a defect in the host cell, such as the dal genes from B. subtilis or B. lichenifor-mis, or one which confers antibiotic resistance such as ampi-cillin, kanamycin, chloramphenicol or tetracyclin resistance.
Furthermore, the vector may comprise Aspergillus selection markers such as amdS, argB, niaD and sC, a marker giving rise to hygromycin resistance, or the selection may be accomplished by co-transformation, e.g. as described in WO 91/17243.
io While intracellular expression may be advantageous in some respects, e.g. when using certain bacteria as host cells, it is generally preferred that the expression is extracellular.
Procedures suitable for constructing vectors of the invention encoding an a-amylase , and containing the promoter, i5 terminator and other elements, respectively, are well known to persons skilled in the art icf., for instance, Sambrook et al.
(1989) ] .
Host cells The cell of the invention, either comprising a DNA con Zo struct or an expression vector of the invention as defined above, is advantageously used as a host cell in the recombinant production of the a-amylase of the invention. The cell may be transformed with the DNA construct of the invention encoding the amylase, conveniently by integrating the DNA construct (in is one or more copies) in the host chromosome. This integration is generally considered to be an advantage as the DNA sequence is more likely to be stably maintained in the cell. Integration of the DNA constructs into the host chromosome may be performed according to conventional methods, e.g. by homologous or 3o heterologous recombination. Alternatively, the cell may be transformed with an expression vector as described above in connection with the different types of host cells.
The cell of the invention may be a cell of a higher organism such as a mammal or an insect, but is preferably a 35 microbial cell, e.g. a bacterial or a fungal (including yeast) cell.

Examples of bacterial host cells which, on cultivation, are capable of producing the enzyme of the invention are gram-positive bacteria such as strains of Bacillus, such as strains of B. subtilis, B. Iicheniformis, B. lentus, B.
s clausii, B. brevis, B. stearothermophilus, B. alkalophilus, B.
amyloliquefaciens, B. coagulans, B. circulans, B. lautus, B.
megaterium or B. thuringiensis, or strains of Streptomyces, such as S. lividans or S. murinus, or gram-negative bacteria such as Escherichia coli. The transformation of the bacteria io may be effected by protoplast transformation, electroporation, conjugation, or by using competent cells in a manner known per se (cf. Sambrook et al., supra).
The yeast organism may favourably be selected from a species of Saccharomyces or Schizosaccharomyces, e.g.
is Saccharomyces cerevisiae. The filamentous fungus may advan tageously belong to a species of Aspergillus, e.g. Aspergillus oryzae or Aspergillus niger. Fungal cells may be transformed by a process involving protoplast formation and transformation of the protoplasts followed by regeneration of the cell wall in a zo manner known per se. A suitable procedure for transformatic: of Aspergillus host cells is described in EP 238 023.
Industrial Applications Owing to their activity at alkaline pH values, the a amylases of the invention are well suited for use in a variety zs of industrial processes, in particular the enzyme finds potential applications as a component in detergents, e.g.
laundry and hard surface cleaning detergent compositions, but it may also be useful in the production of sweeteners and ethanol from starch. Thus, it may be used in conventional starch-3o converting processes, such as liquefaction and saccharification processes described in US Patent No. 3,912,590 and EP patent publications Nos. 252,730 and 63,909.
The alkaline a-amylase of the invention may also be used in the production of lignocellulosic materials, such as pulp, 35 paper and cardboard, from starch reinforced waste paper and cardboard, especially where repulping occurs at pH above 7 and where amylases ca:: facilitate the disintegration of the waste material through degradation of the reinforcing starch. The a-amylase of the invention is especially useful in a process for producing a papermaking pulp from starch-coated printed paper.
s The process may be performed as described in WO 95/14807, comprising the following steps:
a) disintegrating the paper to produce a pulp, b) treating with a starch-degrading enzyme before, during or after step a), and to c) separating ink particles from the pulp after steps a) and b).
The a-amylases of the invention may also be very useful in modifying starch where enzymatically modified starch is used in papermaking together with alkaline fillers such as calcium is carbonate, kaolin and clays. With the alkaline a-amylases of the invention it becomes possible to modify the starch in the presence of the filler thus allowing for a simpler integrated process.
The a-amylase of the invention may also be very useful in~
zo textile desizing. In the textile processing industry, a-amylases are traditionally used as auxiliaries in the desizing process to facilitate the removal of starch-containing size which has served as a protective coating on weft yarns during weaving. Complete removal of the size coating after weaving is zs important to ensure optimum results in the subsequent pro-cesses, in which the fabric is scoured, bleached and dyed.
Enzymatic starch break-down is preferred because it does not involve any harmful effect on the fiber material. In order to reduce processing cost and increase mill throughput, the 3o desizing processing is sometimes combined with the scouring and bleaching steps. In such cases, non-enzymatic auxiliaries such as alkali or oxidation agents are typically used to break down the starch, because traditional a-amylases are not very compatible with high pH levels and bleaching agents. The non-3s enzymatic breakdown of the starch size does lead to some fiber darrtage because of the rather aggressive chemicals used.
Accordingly, it would be desirable to use the a-amylases of the invention as they have an improved performance in alkaline solutions. The a-amylases may be used alone or in combination with a cellulase when desizing cellulose-containing fabric or textile.
s The a-amylases of the invention may also be very useful in a beer-making process; the a-amylases will typically be added during the mashing process.
Detergent Compositions According to the invention, the a-amylase may typically be io a component of a detergent composition, e.g., a laundry detergent composition. As such, it may be included in the detergent composition in the form of a non-dusting granulate, a stabilized liquid, or a protected enzyme. Non-dusting granulates may be produced, e.g., as disclosed in US 4,106,991 and is 4,661,452 (both to Novo Industri A/S) and may optionally be coated by methods known in the art. Examples of waxy coating materials are polyethylene oxide) products (polyethyleneglycol, PEG) with mean molecular weights of 1000 to 20000; ethoxylated nonylphenols having from 16 to 50 ethylene oxide units;
2o ethoxylated fatty alcohols in which the alcohol contains from 12 to 20 carbon atoms and in which there are 15 to 80 ethylene oxide units; fatty alcohols; fatty acids; and mono- and di- and triglycerides of fatty acids. Examples of film-forming coating materials suitable for application by fluid bed techniques are is given in patent GS 1483591. Liquid enzyme preparations may, for instance, be stabilized by adding a polyol such as propylene glycol, a sugar or sugar alcohol, lactic acid or boric acid according to established methods. Other enzyme stabilizers are well known in the art. Protected enzymes may be prepared ao according to the method disclosed in EP 238,216.
The properties of the alpha-amylase of the invention make it particularly suitable for use in alkaline detergents, e.g.
at pH 9.5-10.5, and for washing at low temperatures, e.g. 20-40°C.
35 The detergent composition of the invention may be in any convenient form, e.g. as powder, granules, paste or liquid. A

liquid detergent may be aqueous, typically containing up to 70%
water and 0-30% organic solvent, or non-aqueous.
The detergent composition comprises one or more surf actants, each of which may be anionic, nonionic, cationic, or s amphoteric (zwitterionic). The detergent will usually contain 0-50% of anionic surfactant such as linear alkylbenzene-sulfonate (LAS), alpha-olefinsulfonate (AOS), alkyl sulfate (fatty alcohol sulfate) (AS), alcohol ethoxysulfate (AEOS or AES), secondary alkanesulfonates (SAS), alpha-sulfo fatty acid io methyl esters, alkyl- or alkenylsuccinic acid, or soap. It may also contain 0-40% of nonionic surfactant such as alcohol ethoxylate (AEO or AE), alcohol propoxylate, carboxylated alcohol ethoxylates, nonylphenol ethoxylate, alkylpolygly-coside, alkyldimethylamine oxide, ethoxyiated fatty acid is monoethanolamide, fatty acid monoethanolamide, or polyhydroxy alkyl fatty acid amide (e. g. as described in WO 92/06154).
The detergent composition may additionally comprise one or more other enzymes, such as pullulanase, esterase, lipase, cutinase, protease, cellulase, peroxidase, or oxidase, e.g., ao laccase.
Normally the detergent contains 1-65% of a detergent builder or complexing agent such as zeolite, diphosphate, tri-phosphate, phosphonate, citrate, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetri-zs aminepentaacetic acid (DTMPA), alkyl- or alkenylsuccinic acid, soluble silicates or layered silicates (e. g. SKS-6 from Hoechst).
The detergent builders may be subdivided into phosphorus containing and non-phosphorous-containing types. Examples of 3o phosphorus-containing inorganic alkaline detergent builders include the water-soluble salts, especially alkali metal pyrophosphates, orthophosphates, polyphosphates and phospho-nates. Examples of non-phosphorus-containing inorganic builders include water-soluble alkali metal carbonates, borates and 3s silicates as well as layered disilicates and the various types of water-insoluble crystalline or amorphous alumino silicates of which zeolites is the best known representative.

WO 99/:12567 PCT/DK99/00066 Examples of suitable organic builders include alkali metal, ammonium or substituted ammonium salts of succinates, malonates, fatty acid malonates, fatty acid sulphonates, carboxymethoxy succinates, polyacetates, carboxylates, polycar-s boxylates, aminopolycarboxylates and polyacetyl carboxylates.
The detergent may also be unbuilt, i.e. essentially free of detergent builder.
The detergent may comprise one or more polymers. Examples are carboxymethylcellulose (CMC), poly(viny.~-ayrrolidone) (PVP), ~o polyethyleneglycol (PEG), polyvinyl alc~_:ol) (PVA), poly carboxylates such as polyacrylates, polymaleates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers.
The detergent composition may contain bleaching agents of is the chlorine/bromine-type or the oxygen-type. The bleaching agents may be coated or encapsulated.
Examples of inorganic chlorine/bromine-type bleaches are lithium, sodium or calcium hypochlorite or hypobromite as well as chlorinated trisodium phosphate. Examples of organic zo chlorine/bromine-type bleaches are heterocyclic N-bromo and N-chloro imides such as trichloroisocyanuric, tribromoiso-cyanuric, dibromoisocyanuric and dichloroisocyanuric acids, and salts thereof with water solubilizing cations such as potassium and sodium. Hydantoin compounds are also suitable. The Zs bleaching system may also comprise peroxyacids of, e.g., the amide, imide, or sulfone type.
The oxygen-type bleach may be an inorganic persalt, preferably with a bleach activator, or a peroxy acid compound.
Examples of inorganic persalts are alkali metal perborates, 3o both tetrahydrates and monohydrates, alkali metal percarbonates, persilicates and perphosphates. The activator may be tetraacetylethylenediamine (TAED) or nonanoyloxybenzene-sulfonate (NOBS) .
The enzymes of the detergent composition of the invention 3s may be stabilized using conventional stabilizing agents, e.g. a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol, lactic acid, boric acid, or a boric acid derivative such as, e.g., an aromatic borate ester, and she composition may be formulated as described in, e.g., WO 92/19709 and WO
92/19708. The enzymes of the invention may also be stabilized by adding reversible enzyme inhibitors, e.g., of the protein s type as described in EP 0 544 777 B1.
The detergent may also contain other conventional deter-gent ingredients such as, e.g., fabric conditioners including clays, deflocculant material, foam boosters, foam depressors, suds suppressors, anti-corrosion agents, soil-suspending ~o agents, anti-soil-redeposition agents, dyes, dehydrating agents, bactericides, optical brighteners, or perfume.
The pH (measured in aqueous solution at use concen-tration) will usually be neutral or alkaline, e.g. in the range of 7-11.
i5 More specifically, the alpha-amylase of the invention may be incorporated in any of the detergent formulations described in WO 96/23873.
The a-amylases of the invention may be incorporated in concentrations conventionally employed in detergents. It is at Zo present contemplated that, in the detergent composition of the invention, the a-amylase may be added in an amount correspon-ding to 0.00001-1 mg (calculated as pure enzyme protein) of a-amylase per liter of wash liquor.
The present invention is further illustrated in the z5 following examples which are not intended to be in any way limiting to the scope of the invention as claimed.
EXAMPLES
Host organism:
Escherichia coli SJ2 is described in Diderichsen, B., ao Wedsted, U., Hedegaard, L., Jensen, B.R., Sjoholm, C. (1990) Journal of Bacteriology, Vo1.172, No. 8, p. 4315-4321.
Plasmids:
The gene bank vector was pSJ1678 which is further disclosed in W094/19454 which is hereby incorporated by 3s reference.

The gene bank vector pSJ1678 is further disclosed in WO
94/19454 which is hereby incorporated by reference.
Model deterqent:
A/P (Asia/Pacific) Model Detergent has the following s composition: 20% STPP (sodium tripolyphosphate), 25% Na~SO"
15% Na~C03, 20% LAS (linear alkyl benzene sulfonate, Nansa 80S) , S% C1~-C,5 alcohol ethoxylate (Dobanol 25-7) , 5% Na2Siz05, 0.3%
NaCl.
Example 1 io Cloning of alpha-amylase into E. coli DNA was isolated from Bacillus sp. NCIMB 40916 by the method of Pitcher, D. G., Saunders,N. A., and Owen, R. J.
(1989) Lett. Appl. Microbiol. 8, 151-156. Chromosomal DNA was partially digested with the restriction enzyme Sau3AI. The is fragments were cloned into the BamHI site of the cloning vector pSJ1678, as shown in Figure 4 and transformed into Escherichia coli SJ2, thereby creating a gene library of Bacillus sp. NCIMB
40916.
This gene library was screened for alpha amylase activity 2o and the strain showing alpha amylase activity was termed JA388.
This Escherichia coli strain JA388 which was deposited and given the accession number DSM 12662, and which harbours the plasmid termed pJA388 encoding the alpha amylase was used for DNA sequencing.
is Example 2 Sequencing of DNA and alpha-amylase The Alpha amylase gene cloned in plasmid pJA388 was characterized by DNA sequencing by primer walking, using the Taq deoxyterminal cycle sequencing kit (Perkin Elmer, USA), 3o fluorescent labeled terminators and appropriate oligonucleotides as primers.
Analysis of the sequence data was performed according to Devereux et al. (1984) Nucleic Acids Res. 12, 387-395. The sequence corresponds to the DNA sequence shown in SEQ ID N0: 1.
35 The predicted protein sequence of the alpha amylase including the signal peptide and the mature alpha amylase are presented in SEQ ID N0: 2. The deduced N-terminal sequence was verified by sequencing 34 amino acids a~ the N-terminal of the protein.
Example 3 s Production of alpha-amylase E, coli JA388 harboring plasmid pJA388 was cultivated over night in LB-broth containing chloramphenicol 10 ~.g/ml, 37 °C, 250 rpm. Cells were harvested from 2.7 1 culture broth by centrifugation at 6000 rpm for 15- minutes. The intracellular io located amylase was released from the cells by using the following osmotic shock procedure:
1) Cells were resuspended and washed in 500 ml 10 mM
Tris- HC1, pH 7.0 (EKV-buffer) followed by centrifugation.
2) Cells were resuspended in 75 ml 20% sucrose, 30 mM
is Tris-HC1 pH 8, 1 mM EDTA and added Lysozyme to a concentration of 5 mg/ml.
3 ) The solution was incubated 15 min on ice followed by centrifugation. The majority of the amylase was now contained in the supernatant.
2o The supernatant was dialyzed overnight against 10 1 in EKV-buffer with one buffer change to decrease the high concentration of sucrose. The solution was filtered through a 0.45 y.m membrane vacuum filter.
The enzyme solution was applied on a Pharmacia Q
z5 Sepharose column FF previously equilibrated in EKV-buffer, pH
7, and the column was washed with EKV-buffer. Bound proteins were eluted with a linear NaCl gradient from 0-500 mM over 10 column volumes. Amylase containing fractions were pooled and dialyzed against EKV-buffer over night.
3o The solution was then applied on a Q Sepharose column FF
previously equilibrated in EKV-buffer, pH 8, the column was washed with EKV-buffer, and the amylase was eluted with a linear NaCl gradient from 0-500 mM over ZO column volumes.
Amylase containing fractions were pooled.
as A Phenyl Superose column previously equilibrated in EKV-buffer, pH 8 containing 1 M ammonium sulfate was loaded with the enzyme solution added ammonium sulfate to a concentration of 1 M. Unbound material was washed out with the ammonium sulfate buffer and the column was eluted with a linear NaCl gradient from 1-0 M ammonium sulfate over 20 column volumes.
Amylase containing fractions were pooled.
The purified amylase was analyzed by SDS-PAGE and only one band was obtained after staining with Coomasie Blue.
Example 4 Washing test o Washing performance was evaluated by washing soiled test swatches for 15 minutes at 25°C in a detergent solution with the alpha-amylase of the invention.
The detergent used was the A/P Model Detergent described above at 3 g/1 having pH 10.5, or a commercial detergent from i5 Malaysia (FAB Total from Colgate) at 3 g/1 having a pH of approx. 9.7. The purified amylase of Example 3 was added to the detergent solution at the concentration indicated below. The test swatches were soiled with orange rice starch (CS-28 swatches available from CFT, Center for Test Material, zo Holland) .
After washing, the swatches were evaluated by measuring the remission at 460 nm. The results are expressed as DR -remission of the swatch washed with the alpha-amylase minus the remission of a swatch washed at the same conditions without the alpha-amylase.
Alpha-amylase DR OR
concentration Model detergent Malaysian detergent (mg enzyme protein / 1) 0 (reference) - 0 - 0 0.1 0.9 1 0.2 1.9 1.3 0.5 3 2.4 1.5 4.1 4.3 The results are shown in rigures S and 6. The results demonstrate that the alpha-amylase of the invention is effective in both detergents at highly alkaline pH.

SEQUENCE LISTING
<110> Novo Nordisk A!S
<120> Alkaline Bacillus Amylase <130> 5942 <140>
<141>
<160> 2 <170> PatentIn Ver. 2.0 <210> 1 <211> 1599 <212> DNA
<213> Bacillus sp.
<220>
<221> CDS
<222> (1)..(1599) <220>
<221> sig peptide <222> (1)..(93) <220>
<221> mat_peptide <222> (94)..(1596) <400> 1 atg caa aac aca gcg aaa aac tcc atc tgg cag agg gtg cgc cac agc 48 Met Gln Asn Thr Ala Lys Asn Ser Ile Trp Gln Arg Val Arg His Ser gcc att gcc tta tcc get ctc agt tta tcc ttt ggc ctg cag gcc agc 96 Ala Ile Ala Leu Ser Ala Leu Ser Leu Ser Phe Gly Leu Gln Ala Ser gag tta cca caa att cca cca cag cag gtg aac aac acc atg tac cag 144 Glu Leu Pro Gln Ile Pro Pro Gln Gln Val Asn Asn Thr Met Tyr Gln gca ttt tat tgg gat gcc tac cct ggc ctt tgg gcc aat tta ccg gcc 192 Ala Phe Tyr Trp Asp Ala Tyr Pro Gly Leu Trp Ala Asn Leu Pro Ala atg gcg gcc cct ttg gcc gag cgt ggc att acc tcg atg tgg ttg ccg 240 Met Ala Ala Pro Leu Ala Glu Arg Gly Ile Thr Ser Met Trp Leu Pro ccc gcc gcc aaa ggc atg aat ggt act ttc agt gtc ggt tac gat gta 288 Pro Ala Aia Lys Gly Met Asn Gly Thr Phe Ser Val Gly Tyr Asp Val tac gat ttc tgg gat ctg ggc gag ttt aac caa aaa ggc acc acc gcc 336 Tyr Asp Phe Trp Asp Leu Gly Glu Phe Asn Gln Lys Gly Thr Thr Ala acc cgt tac ggt act cgt cag cag ctg caa caa gca ctg agt get ctg 389 Thr Arg Tyr Gly Thr Arg Gln Gln Leu Gln Gln Ala Leu Ser Ala Leu gac caa ctg ggt att cag gcc tat ttt gat gtg gtg ttt aac cac cgc 432 Asp Gln Leu Gly Ile Gln Ala Tyr Phe Asp Val Val Phe Asn His Arg atg ggc gcc gat gca cag gag aat att cct ggc ttt ggc ctg gcc tgg 480 Met Gly Ala Asp Ala Gln%Glu Asn Ile Pro Gly Phe Gly Leu Ala Trp acc gag tat cat ctg caa ggt cgt cag gcg cat tat acc cag caa aac 528 Thr Glu Tyr His Leu Gln Gly Arg Gln Ala His Tyr Thr Gln Gln Asn tgg ggc tac ttg tgg cac gac ttt gac tgg aac tgg acc gcg ttt aat 576 Trp Gly Tyr Leu Trp His Asp Phe Asp Trp Asn Trp Thr Ala Phe Asn ggc tcc gac aat cag ctc tac ccc ggc aaa tgg tgg ggc aat acc ttc 624 Gly Ser Asp Asn Gln Leu Tyr Pro Gly Lys Trp Trp Gly Asn Thr Phe cac ttc cct tat ttg atg ggt gag gat gtc gat tac aac cgc ttt gaa 672 His Phe Pro Tyr Leu Met Gly Glu Asp Val Asp Tyr Asn Arg Phe Glu gtg cag cag gaa atg aaa gcc tgg ggc gag tgg atc atc aac agc gtt 720 Val Gln Gln Glu Met Lys Ala Trp Gly Glu Trp Ile Ile Asn Ser Val ggc ttt agc ggc ttt cgg atg gat gcc atc gcc cat gtc gat acc gat 768 Gly Phe Ser Gly Phe Arg Met Asp Ala Ile Ala His Val Asp Thr Asp ttt acc cgt gac tgg atc aa~ cac gtg cag tgg gcc acc agt gag gat 816 Phe Thr Arg Asp Trp I1e Asn His Va1 Gln Trp Ala Thr Ser G_u Asp gtg ttc ttt gtc get gaa gcc tgg gtc agt gat atc aac ggc tat ctg 864 Val Phe Phe Val Ala Glu Ala Trp Val Ser Asp Ile Asn Gly Tyr Leu gat gca gtc aat acg ccg cat ttg cgc get ttt gat ttc aat ttg cgc 912 Asp Ala Val Asn Thr Pro His Leu Arg Ala Phe Asp Phe Asn Leu Arg gaa gac ttc gtt get tta agc agc ggt agc aaa gac atg cgt tgg tgg 960 Glu Asp Phe Val Ala Leu Ser Ser Gly Ser Lys Asp Met Arg Trp Trp ggc ggt ctg gtc aat agc cag cac cgt gat cgg gcg gtc act ttt gtc 1008 Giy Gly Leu Val Asn Ser Gln His Arg Asp Arg Ala Val Thr Phe Val gat aac cac gat acc agc cgg gcc ggc aac cct tat ggc atg ccg cag 1056 Asp Asn His Asp Thr Ser Arg Ala Gly Asn Pro Tyr Gly Met Pro Gln gtg atc aac tac aag aac cag gcc tac get tac att ctg ttg cgt gag 1109 Val Ile Asn Tyr Lys Asn Gln Ala Tyr Ala Tyr Ile Leu Leu Arg Glu cat ggg gtg ccg act gtg ttt gcc cgc gat tac gac gaa ttt ggc atg 1152 His Gly Val Pro Thr Val Phe Ala Arg Asp Tyr Asp Glu Phe Gly Met gcg cca acg ctg gat aaa ttg att gag gcg cgc cgc tac ttt get tat 1200 Ala Pro Thr Leu Asp Lys Leu Ile Glu Ala Arg Arg Tyr Phe Ala Tyr ggt cct ggc cat gag tac tcc ggc aat acc gag gcc gtc tac gcc tat 1248 Gly Pro Gly His Glu Tyr Ser Gly Asn Thr Glu Ala Val Tyr Ala Tyr gtg cgc gaa ggg ctt agc act gtg ccg ggt acc ggt ctg gtg atg ctg 1296 Val Arg Glu Gly Leu Ser Thr Val Pro Gly Thr Gly Leu Val Met Leu ata tcg ggt cga aac tgg ggt ggt cag cag tcg ttc acc atc aac agc 1349 Ile Ser Gly Arg Asn Trp Gly Gly Gln Gln Ser Phe Thr Ile Asn Ser cac cag ccg aat acc acc t~~ tac gat tat acc ggc aat gtt agc ggc 1392 His Gln Pro Asn Thr Thr Phe Tyr Asp Tyr Thr Gly Asn Val Ser Gly acg gtg acc acc aat gcg cag ggc tat ggc agc ttc ccg gtc act atg 1940 Thr Val Thr Thr Asn Ala Gln Gly Tyr Gly Ser Phe Pro Val Thr Met acg gaa agt acc ggt tgg tca gtc ttg ggt acc aca atc caa tgg tgg 1488 Thr Glu Ser Thr Gly Trp Ser Val Leu Gly Thr Thr Ile Gln Trp Trp cac tca gcc ggg atc cat tac cct gcg gat gac caa gga tgt tgg cta 1536 His Ser Ala Gly Ile His Tyr Pro Ala Asp Asp Gln Gly Cys Trp Leu tgg ctt ttc gtt gtt ctt cac cgg cag cag tgc gga act gac caa ctg 1589 Trp Leu Phe Val Val Leu His Arg Gln G1n Cys Gly Thr Asp Gln Leu ggg cgg cgg tat tga 1599 Gly Arg Arg Tyr <210> 2 <211> 532 <212> PRT
<213> Bacillus sp.
<400> 2 Met Gln Asn Thr Ala Lys Asn Ser Ile Trp Gln Arg Val Arg His Ser Ala Ile Ala Leu Ser Ala Leu Ser Leu Ser Phe Gly Leu Gln Ala Ser Glu Leu Pro Gln Ile Pro Pro Gln Gln Val Asn Asn Thr Met Tyr Gln Ala Phe Tyr Trp Asp Ala Tyr Pro Gly Leu Trp Ala Asn Leu Pro Ala Met Ala Ala Pro Leu Ala Glu Arg Gly Ile Thr Ser Met Trp Leu Pro Pro Ala Ala Lys Gly Met Asn Gly Thr Phe Ser Val Gly Tyr Asp Val Tyr Asp Phe Trp Asp Leu Gly Glu Phe Asn Gln Lys Gly Thr Thr Ala Thr Arg Tyr Gly Thr Arg Gln Gln Leu Gln Gln Ala Leu Ser Ala Leu Asp Gln Leu Gly Ile Gln Ala Tyr Phe Asp Val Val Phe Asn His Arg Met Gly Ala Asp Ala Gln Glu Asn Ile Pro Gly Phe Gly Leu Ala Trp Thr Glu Tyr His Leu Gln Gly Arg Gln Ala His Tyr Thr Gln Gln Asn Trp Gly Tyr Leu Trp His Asp Phe Asp Trp Asn Trp Thr Ala Phe Asn Gly Ser Asp Asn Gln Leu Tyr Pro Gly Lys Trp Trp Gly Asn Thr Phe His Phe Pro Tyr Leu Met Gly Glu Asp Val Asp Tyr Asn Arg Phe Glu Val Gln Gln Glu Met Lys Ala Trp Gly Glu Trp Ile Ile Asn Ser Val Gly Phe Ser Gly Phe Arg Met Asp Ala Ile Ala His Val Asp Thr Asp Phe Thr Arg Asp Trp Ile Asn His Val Gln Trp Ala Thr Ser Glu Asp Val Phe Phe Val Ala Glu Ala Trp Val Ser Asp Ile Asn Gly Tyr Leu Asp Ala Val Asn Thr Pro His Leu Arg Ala Phe Asp Phe Asn Leu Arg Glu Asp Phe Val Ala Leu Ser Ser Gly Ser Lys Asp Met Arg Trp Trp Gly Gly Leu Val Asn Ser Gln His Arg Asp Arg Ala Val Thr Phe Val Asp Asn His Asp Thr Ser Arg Ala Gly Asn Pro Tyr Gly Met Pro Gln WO 99/d2567 PCT/DK99/00066 Val Ile Asn Tyr Lys Asn Gln Ala Tyr Ala Tyr Ile Leu Leu Arg Glu His Gly Val Pro Thr Val Phe Ala Arg Asp Tyr Asp Glu Phe Gly Met Ala Pro Thr Leu Asp Lys Leu Ile Glu Ala Arg Arg Tyr Phe Ala Tyr Gly Pro Gly His Glu Tyr Ser Gly Asn Thr Glu Ala Val Tyr Ala Tyr 405 910 ' 915 Val Arg Glu Gly Leu Ser Thr Val Pro Gly Thr Gly Leu Val Met Leu Ile Ser Gly Arg Asn Trp Gly Gly Gln Gln Ser Phe Thr Ile Asn Ser His Gln Pro Asn Thr Thr Phe Tyr Asp Tyr Thr Gly Asn Val Ser Gly Thr Val Thr Thr Asn Ala Gln Gly Tyr Gly Ser Phe Pro Val Thr Met Thr Glu Ser Thr Gly Trp Ser Val Leu Gly Thr Thr Ile Gln Trp Trp His Ser Ala Gly Ile His Tyr Pro Ala Asp Asp Gln Gly Cys Trp Leu Trp Leu Phe Val Val Leu His Arg Gln Gln Cys Gly Thr Asp Gln Leu Gly Arg Arg Tyr

Claims (21)

1. An alpha-amylase which is:
a) a polypeptide produced by Bacillus sp. NCIMB 40916, or b) a polypeptide having an amino acid sequence as shown in positions 32-532 of SEQ ID NO: 2, or c) a polypeptide encoded by the alpha-amylase encoding part of the DNA sequence cloned into a plasmid present in Escherichia coli DSM 12662, or d) an analogue of the polypeptide defined in (a) or (b) which:
i) is at least 60 % homologous with said polypeptide, or ii) is derived from said polypeptide by substitution, deletion and/or insertion of one or more amino acids.

2. An alpha-amylase which has an activity at pH 10.5 which is at least two times higher than the activity at pH 7.3 when measured at 37°C.

3. An alpha-amylase which has an activity at pH 9.5 which is at least 4 times higher than the activity at pH 7.3 when measured at 37°C.

4. An alpha-amylase which has an optimum pH of about 9.5 when measured at 37°C.

5. The alpha-amylase of any preceding claim which is from a strain of Bacillus, preferably Bacillus sp. NCIMB 40916.

6. The alpha-amylase of any preceding claim which retains more than 90 % of its activity after 20 minutes incubation at 25°C in a solution of 3 g/l of a test detergent containing 20%
STPP, 25% Na2SO4, 15% Na2CO3, 20% LAS, 5% C12-C15 alcohol ethoxylate, 5% Na2Si2O5, 0.3% NaCl at pH 10.5 and 6 degrees German hardness, and retains less than 90 % of its activity after 20 minutes incubation at 30°C in the same solution.

7. The alpha-amylase of any preceding claim which has a molecular weight of about 55 kDa as determined by SDS-PAGE.

8. The alpha-amylase of any preceding claim which has an iso-electric point of about 5 as determined by isoelectric focusing.

9. The alpha-amylase of any preceding claim in the form of a detergent additive which is a non-dusting granulate or a stabilized liquid.

10. An isolated DNA sequence which encodes the alpha-amylase of any of preceding claim.

11. An isolated DNA sequence which encodes an alpha-amylase and comprises:
a) the DNA sequence shown in positions 94-1596 of SEQ
ID NO: 1, or b) an analogue of the DNA sequence defined in a) which i) is at least 60 % homologous with said DNA
sequence, or ii) hybridizes with said DNA sequence at least 55°C.

12. The DNA sequence according to claim 10 or 11, which is from a bacterium, preferably from Bacillus, most preferably from the strain NCIMH 40916.

13. A recombinant expression vector comprising the DNA
sequence according to any of claims 10-12.

14. A cell transformed with the DNA sequence according to any of claims 10-12 or the recombinant expression vector according to claim 13.

15. The cell according to claim 14, which is a prokaryotic cell, in particular a bacterial cell or an endogenous cell from which said DNA sequence originates.

16. The cell according to claim 15, wherein the cell belongs to Bacillus or Escherichia, preferably E. coli.

17. A method of producing an alpha-amylase, comprising cultivating a cell according to any of claims 14-16 under conditions permitting the production of the alpha-amylase, and recovering the alpha-amylase from the culture.

18. A method for producing the alpha-amylase of any of the preceding claims, comprising cultivating an amylase-producing strain of Bacillus in a suitable nutrient medium, and recovering the alpha-amylase from the culture medium.

19. A detergent composition comprising the alpha-amylase of any of claims 1-9 and a surfactant.

20. The detergent composition of the preceding claim which has a pH of 8.5-11 in aqueous solution, preferably pH 9-10.5

21. The detergent composition of claim 19 or 20 which is a laundry detergent.