Note: Descriptions are shown in the official language in which they were submitted.
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CHEMICAL PULP TREATMENT COMPOSITIONS AND METHODS
FIELD OF THE INVENTION
The present inventian relates to en.zymatiG compositiofis and methods for
treating pitch
problems in chemical }aulp.
BACKGROUND OF THE INVENTION
Wood corrtains about 1 to 1p '~ of pitch or extractives in addition to its
main cornponent.s cel-
Ãufose, herniouiÃose and Iigniri. Major cornporrents of pitch are fatty acids,
trigiycerdies, sterols,
steryl esters arir:i resin acids, such as, for example, abietic acid. Pitch
causes problems in paper
machines by sticking to the rollers and oatrsing spots or holes in the paper
materiaÃ.
Various enzymatic processes have been used to treat pitch problems. WO
00/53843 dis-
cÃases ster-yà esterase enzyme preparations and their use in the manufacture
of paper to hydrolyze
the steryl ester part of pitch.
U.S. Pat. No. 5,066;486 discloses an enzyme prepafatÃon carnprisirrg a
cholesterol esterase
derived from Psecidnmor-ias fragi, and its use to hydrolyze pr_i1p resin.
JP 2000080581 discloses the use of certain peroxidases for the decomposition
of abietic
acid during puÃpinq or paper making processes.
X. Zhang; Pulp & Paper Cariada, 101 :3 (2000), page 59-62, discloses studies
of the ability
of laccase to femove dissolved and colloidal sr,rbsta.nces.
Karlsson et aÃ.. Reactivity of Trametes laccases with fatty and resiri aoids:
Appi. Mioi'obiaÃ.
Biotechnol. (2001) 55:317-320 discloses experiments in which iacoases were
r.ised to treat pitch.
U.S. Paterit afapfic.atiori 20030124710 discloses a process
forsnariuracturirrg a paper mate-
rial by treating a paperrnakirrg pulp process water with a fatty acid
oxidizing enzyme.
U.S. Patent Na. 5,356,517 discloses the use of lipases to hydrolyze
tryglycerides during
peroxy bleaching in the preparation of cherrrÃtherrrrorrrec;:rarrÃeaà pulp.
SUMMARY OF THE = INVENTION
The present inver3tiori relates to composÃtfotis and methods for treating
pitch probÃems in
chemical pulp by treating chemical pulp process waterwith a combination of
aÃipase and aperox
ide source. Afthough not limited to any one theory of operatiori, it is
believed that the addition of a
lipase and peroxide leads to the forrt3atirtri of peracids which in turn
oxidize unsaturated fatty acids
and resin acids thmugh an expoxidation reaction. The rrasuftÃng products are
hydrophilic ar3d are
readily washed trorrr the pulp, tiiereby redticing pitch problems associated
with chernicat pulp.
In another embodiment, the present invention relates to compositions and
methods for
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troatirig pitch problems #n chemical pLilp by treating Ct7emica1 pulp ptocoss
water with a lÃpase, a
peroxide source and an orgat3ic acid.
~ETAtLF-D C3~SCl=til:*TI!2N OF THg tN~ENTtC3N
A"pape=r r-nalcing process" refers to a process wherein a chesnicat pulp is
suspended in wa-
tor, mixed with var#ous add.itiles and then passed to eciuiprncrit for
fcirther processing, e.g., in which
the paper, cardboard, #tss{ae, towel etc. is formed, pressed and dried.
The term 'paper rnaterial" refers to products which can be made aLtt of pulp,
suc~ as pa-
per, iir~erboard, corrugated paperboard, tissue, towels, corrugatod
corit.ainers or boxes.
The term "a papermaking putp" or ~`pulp means atiy chesnical puip which can
be used for
fho productiati of a paper rr3ateira1.
A "chomica( pulp" refo#s ta cliecnlca( pulp {such as Kraft putp or sutfite
pulp) or serriichar-nic.at
ptrlp (wGP), Chemical pulp is usually manufactured by alkaline cooking whereby
rnast of the iigri#rl
and some hemicellulose components are removed. In Kraft ptalpirrg or strlphaÃe
cooking, socÃiurn
stilphitte or seditim hydrrsxide are. generally used as princ9pal cooking
chemicals. In szich paip, as
a resu3t of the alkaline cooking, the trÃgtyc:eride part of pitch wili be
hydrolyzed into fatty acids and
glycerot.
In a particular embodiment of the tise and the process of the inver-tion., the
chemical ptilp
is a Kraft pulp oi, a so#fite pulp. In particular embodiments, the Kraft pulp
is bleached Kraft pulp, for
example softwood bleached Kraft (SWBK, also cailed NBKP (Nadel Holz BleachecÃ
Kraft Pulp)),
hardwood bleached Kraft (HWBK, also called LBKP (!~acib Holz Bleached Kraft
Pulp and)) or a
Fnixttire thereof
The Kraft pulp ta be treated may be a bleached Kraft pulp, which may consist
of softwood
bleached Kraft (SWBK, also called NBKP (Nadel Holz Steached Kraft Pulp)),
hardwood bleached
Kraft (HWBK, also called LBKP (Laub Holz Bleached Kraft Pulp and)) or a
mi3ctiire of these
The ptilp to be Ãiseci in the process of the invention is a st3spensson of
chemical ptiip. The
ptilp to be used in the process of the iilveot#arr may ccunprise at least 10%,
at least 20 !k, at least
301~4: at least 40%, at least 50%, at least 60%, at least 70p/a, at least 80%,
at least 90%, at least
95%, or 100% of r:t3efyiÃcai pulp (sucii as Kraft pulp o3' sulfite pulp), The
percceritage of chemical
pulp iios within the range of 7-100%. In partictilar embodiments, the
percentage of chemical pulp
(such as Kraft pulp or sulfite pulp) ties withiri the range of 1-99%, 2-98%, 3-
97%, 4-96%, 5-95%, 6-
94%, 7-93%. 3-~~ io, 831 io, 10-90%, 15-85%r 2#3-8E}Qlo, 25-7510, 30-70 %, 40-
60 !o, or 45-55%.
In accordance with the pr'ese.r3t invention, cttemicat pulp process water is
treated with a
combination of a lipase and a peroxide source. Such chemical pulp process
water cor3tains pitch
cat$Esing components, stich as, fatiy ac#ds, trigiycerclies: sterols, steryl
esters and/or resin acids (for
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example, abietic acid). The process of the iriveration is particularly
applicable to the reduction of
comf.~ourids coiistitutiily the pitch during a pcr(piiig or paper makirig
process, e.g. to avoid pitch
troÃibtes.
Any suitable lipase may be used: Lipases iriclude the enzymes classified by EC
3.1.1.3. Ref-
erence is made to the Recornrner3ctations (1992} of the Nomenclature
Cornrnittee of the liiteri;atiofiai
Union of Biochemistry and Molecular Bioioqy, Acadernio Press Inc., 199.2
In a preferred ernirodirneni of the present inuei3tion, the lipase is
preferably of microbial ori-
gin, in particular of bacterial, fiingaf or yeast origiri. The lipase may be
derived irain any soatrce, in-
ciudirig, for example, a strain of Absidia, in particular Abstdia biakesleena
and Abslrfia corymbifera, a
strafii of Acirrvrnofaecter, in parÃiccilar Achmmobacter iophagus, a sfraiii
of Aeromonast a strairi of
Rfterrmrfa, in parficiatar Altemaria brassiciote, a strairi of Aspergiflus, in
parkicuiar Aspergiltus niger and
As,vergillÃrs flavus, a strain of Achror73obacter, in parlicular Achr-
omofaacter io;afzegcts, a strain of
Aur-eobasrdifrm, in particular Aureoiaasidr'cirrr pullula#?s, a sÃrain of
Bacillus, in pailicular Bacillus
fJLll')'tlius, Bacillus Sfm-c?rtJffief'rT33pFJi1Ã!s and Bac1llus subtilis, a
strain of Beauveria, a stiairt of Bro-
1 a chc[t3rix, in pai'ticialar Brwtaottirix fllerrnoscftata, a strain of
Cario'itfa, in pai'ticular Carrdide cyt-
rrzdracea (Candida rugasa), Candida paratipolytica, and Carirllrfa
ar7tarctica, a strair3 nf Chromcbac-
ter, in particular Chrot-nobacter uiscosum, a strain of Coprinus, in
particrilat' Crapr-inass cinerius, a strain
of Ft.isar"it.ii'?s, in particular Fusarium oxyspcrcem, Fusariurrr solani,
Fusadum solani prsi, anr;! F'usarium
ro.wurrt oÃrlmorcrm, a strain of Geoftrcum, in particular Gootricurn
penicitlatum, a strain of Narrser3ula,
in iaarticÃilar tiansenuta at?rsrnata; a strain of NLrrnicola, in particfilar
Nirmicola farevispora; f-furtricola
bievis var. thermoidea, and Nurnicola ilasofens, a strain of Hyphozyina, a
strain of Lactobacilltis, in
particÃriar Lactahacillus curmtus, a strain of 1Uleter#7ixiÃrtn, a strain of
Mocar; a strain of f'aeciiomyces,
a siraiÃi of Pe.nrcifiiurrr, in padicalar.Pen.i'ci}litrm cyciopiurn,
Aarrici.llfcern crustosurn and PerticitliÃsrn ex
partsum, a strain of PseÃrdarraonas in particular Pseudomorias aeniginosa,
Pseuciomoraas alceli-
genes, Psecrdorr7anas cepacia (syn. 6urkhoicterra cepacia), Pseuctomonas
fluarescens, PseuctQmQ-
ri,as fragi, Pseudamcnas maltQphffia, Psecrcfamonas meridociraa,
Psetrctomorras rrrepfritica lipDfytica,
Pseudornorias atcajigenes, Pseudon7anas pientari, Fse<udomonas
iaseudvalealigenes, Pseudomonas
,vuticle, Psecidofrrolras stutzeri, and ~Oseucinrrronas wisconssnerrsist a
strain of Rhizoctonia, in particLt-
far Rt}izncfor7ia sotani, a strain of Rhizarrrucor, in parlicuiar Rhizor3yucor
rraiehei: a straiii of R17izopus,
in partictilar Rhizopcrs japonicus, Risi-vopÃrs micrnspnws and ti17izvpus
nodosus, a strain of
f?hodcsporidir.rrrt, in particular '13or;tosporridiÃrrn tortrloicies, a strain
of R1?odotorufa, in particular
Rhcdotorxr}a gfudnfs, a strairi of S,oarobafomyces, in pailicular
Sporobofarn,}ces shibatanus, a strain
of 7berr-ncrrnyces, in pailicWar 777er.momyces tanuginosus (formerly
Ffurrricofa lanugihosa), a strain of
TI?iarDsparella, in particular Ttiiarosporella plfaseoiiria, a strain of
Tricrhadenna, iri pailicular Tricho-
derma faarziarrurri, aiid Trichacferrna reesei, and/or a strain of
t/etticilfium.
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in a preferred embodiment, the 3ipase is derived from a strain of
Aspergillils, a strain of
Achrarnabacter, a strairi of Baci;'cts, a strain of Cendida, a strac in of
C17raniobacter, a strain of Filsa-
ritirn, a strain of Huinivola, a strain of Nyphozyrna, a strain of
Pse=odononas= a strain of Rhizolnucor,
a strain of Rh6zaptis, or a strain of '7`hettnvrnyces.
Preferred lipases include the lipases described iri U.S. Patent No. 6,074,863
and M
02/055679. Preferred cornmerciai lipases incifide Resinase A2X and Resinase HT
(Hovczyrnes
AtS). In another preferred embortimer7f, the lipase is the Canriirie
ar7ta.rctice lipase A(GALA) or the
Carrcfufa w7tarctica lipase 8(CAt_B) (available from Novozymes A/S)
As tised herein, a"peroxide saLrrce" or #rydrogeri peroxide source" refers to
hydrogen per-
oxide itself or cornpor3erits which cari generate peroxide. The hydrogen
peroxide source may be
added at the beginnirig or dl,friiig the lipase treatment process, e.g., at a
concentration of about
Ã3.001-100 mM, particularly 0.01-50 mM. One scr.rrce of hydrogen peroxide
includes precursors of
hydrogen peroxide, strcb as, e.g., a pertorate or a percarbonate. Anott7er
source of hydrogen
peroxide includes enzymes which are able to convert molecular oxygen and an
orgar3ic or irrvr-
ganic substrate into hydrogen peroxide and the oxidized substrate,
respectively. These enzymes
produce only low levels of hydrogen percxicte. Examples of enzymes which are
capable of produc-
ing hydrogen peroxide inciude, btrt are not limited to, glucose oxidase, urate
oxidase, galactose
oxidase, alcohol oxidase, amine oxidase., amino acid oxidase and cholesterol
oxidase,
Atttraugb not limited to any one theory of cpera#.iori, it is believed that
the addition of a Ii-
pase arid peroxide leads to the farmaficri of peracids which in turn oxidize
ur7saturated fatty acids,
resin acids and other pitch components thrtiugh an epcxida.tiori reaction. The
resulting prcducts
are bydrcphilic and nre readily washed from the pulp, thereby redLrCirIQ or
elimiriating pitch prcb-
ler-ns.
Organio acid(s) may also be added to the pulp, e.g., to enhance the pitch
treatment. Or-
ganic acids refer to any organic stibsfance which contains at least one acidic
group. Examples of
orclariic acids are acetic acid, butyric acid, and linoleio acid. The
concentration of organic acid is
preferably between 0.001 -5Ã70 mM.
In the case of paper and pufp processing, ttle process according to the
iliventi0n caii be
carried out at ar7y pulp production s#age: Tt}e enzyme can be added to ariy
hofdir3g taftk, e.g, to a
pulp storing contairier (storage chest), storage tower, rnixing cYrest or
meterirlg ct7est. The erlzyme
treatment is preferably applied before or after pulp bleach process or in
between the pulp bleaching
stages. The enzyme cari be added to the circulated process water (white water)
origirratirig from
bleactiirig. In a parliwlar ernbcdimeat of a Kr=aft pulping process, ttle
enzyme is added dr,,ring the
brown-stock washing.
In the present context, the term "process water' can incitsde water added as a
raw rr,atertal to
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the paper manufacttiring process; -ritersnediate water products resultirig
from arly step of the process
for mantafactLiririg the paper rnaterial; as well as waste water as aii output
or by-produat of the
process, In a partiaular embodimeirt, the process water is, has been, is
being, or is intended for beii7g
circutatecf or re-circÃrtated, i.e,, re-used in another step of the process.
The term "water ' in turn mearis
any aqueous medium, .sotutton, suspensian, e.g., ordinary tap water, and tap
water in admixture with
variotÃs addifives and adjtÃvants commonly ti5ed in paper manufacturing
processes, In a particular
embodiment the process water has a#ow content of solid (dry) rnafter, e.g.,
below 20%, 18%, 16%,
14%. 12%, 10%, 8%, 7%> 6%, 5%, 4%,3 tb, 20% or beiaw 1% dry tltat.tor.
The process of the inua:3tioÃi may be carded out at conventionai conditions in
the paper and
pulp processÃrtg. The process crsi7ditions will be a firnctioti of the
enzyme(s) applied, the reaction tirne
and the conditions given.
The enzyme and peroxide should be acfded Ãn an effective amount. By the terrn
"'ef#ective
arnouot is snearit ttle amount sufficier7f to achieve ttie desired effect of
reduci#ig or irtliibiting pitch
components, srici=r as, by degrading or converting such components into a
fcsrrn which can be more
readil,y removed from the pfrl,p or ptrlp process water.
In a partic tar embodiment, the dosage of the ispase enzyme is from aborit 0,1
mg enzyme
protein to about M.000 mg enzyme protein (of each enzyme) pertoii of paper
pulp.
The enzymatic treatment can be done at consistency, e.g., 0.5-14 % dry
substarÃoe. In
partioutar embodi:ments, the consistency is within the range of 0.5-45; 0.540;
0.5y35; 0.5y30; 0,54
25; 0.5-20; 0.5-15, t}.5-1 0; 0.5-3; iI,S-6; or 0.5-5% dry stÃbstant;e.
The erizymaffc treatment may be ciarried out at a temperature. of from about
10 to about
10000. i"urther examples of temperature ranges (all `frorn aIaout' and "to
aboue) are the fat#owing;
20-100, 30-100, 35-100, 37-10Ã1, 40-100, 50-100, 60-100, 70-1[t(T, 10-90, 10-
30; 1 t?- i t}, 10-60, and
30-60,-~C, as well as any combiti stion of the upper and lower vatues here
iiidicateci. The temperature
may be frorn about 20 to 90''G, or 20 to 950C, preferabty from about 40 to 7f3
C, or 40 to 751'G.
The enzymatic treatment may be carricd out at a pH of from about 2 to about
12. FLilther
examples of pH ranges (ali 'from about" and `to about") are the following: 3-
12, 4-12, 5-12, 6-12, 7-
12, 8-12, 9-12, 2-11f 2-10, 2A9, 2-8: 4-10, 5-8 as well as arry cornbination
of ÃtÃe upper' arid lower'
vstues here indicated. The pH range rr3ay be from about 2 to 11, preferably
within the range from
about 3-9.
A suitable dtrrativn of the enzymatic treatment may be in the range from a few
seconds to
several hours, e.g, from about 30 seconds to about 48 hours, or from about I
rninute to about 24
hours, or from about I minute to abotit 18 botirs, or from about I minute to
abcÃtrt 12 boc+rs, or from
about I fninute to 5 hours, or fmrn about 1minute to about 2 t7otÃrs, or from
about 1 miltute to about 1
bor.ir, or from abotrt I minute to about 30 riintttes. The reactioii time may
be from about 10 mir7utes to
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3haurs,10 mintites to 10 hotFrs, preferably 15 miriutes to I hour, or 15
miiiutes to 2 hours,
Varioos additives over and above the enzyme and pem)(ide treatrnezit can be
used in the
process or use of the inverttion. Surfactants andtar dispersants are often
present in, and/or added to
a paperr-naking puifs. Thus the process and use of the present invention may
be eari7ed out in the
preseaice of an aiiionic, rion-#or3ic, cationic and+or zwitt.erionio
surfactant and/or dispersar3t
conventionally used in a papermaking i3ulp, Examples of anionic stirfactants
are carboxylates,
suipfiates, sulphonates or phosphates of aikyit sLibst+ttited alkyl or aryl,
i=atty acids are examples of
aliCyf-carboayiates. Examples of non-iotiic surfactants are polyoxyethyiene
compounds, such as
alcohol ethoxyfates, propaxyhMes or mixed ethoxy-lpmpoxyiates, poly-glycerols
aild other polyols, as
well as- ce#fairi btock-copofymers. Examples of cafioriic surfactants are
water-soluble catioriic
polymers, such as ctttailenary ammotiium sutphates and certain amines, e.g,
epichIorobydrin/dimethylarn-ne polymers {EPt-flN9A} arld cr:oss-tiniced
soiotions thereof, polydiallyl
ctirnet.t3yl ammonion3 chloride (DADMAC), UADMACiAcfytamide co-polymers, and
ioriene polyztiers,
such as those rJiselosed in US patents nos. 5,681,862; and 5,575,993. Examples
of zwitterionic or
amphoteric surfactants are betains, glycinates, amino propionates, imino
propionates and various
imidazoiirr-deriuattves. Also the polymers disclosed in US patent no.
5,256,252 may be used.
Aiso according to the invention, surtactants such as the above, incifjding any
combination
thereof may be used in a paper making process. The .atrtot;nt of each
surfactant ir3 such composition
may amount to from about 8 to abotit 40% (w/w) of the compositioti. In
parkicofar embodiments the
amount of each sorfactant is from about 10 to about 38, or from about 12 to
about 36, or from abotit
14 to about 34, or from about 16 to about 34, or from abotit 18 to about 34,
or from abotit 20 to about
34, or from about 22 to abota 34, or from about 24 -to about 34, or fsom about
26 to about 34, or fmm
about 28 to about 32% (w/w).
It is to be understood that the term enzyme, as well as the various enzymes
and enzyrne
classes mentioned herein, enratnpass wild-type enzyrnes, as wef1 as any
variant thereof tbat re-
taixis the activity in c#tiestion. St;ch variants may be produced by
recombina.iit tecboiqoes. The
wiidrtype enzymes may also be prodLiced by recombinant tectrniques, or by
isolation and puri .t'ica-
tÃon from the nattrraf source.
In a particular ernbcrdii-neot the enzyme in question is well-defined, meaning
that only one
rnajor= enzyme component is present. This oati be inferred e.g. by
fÃactionation oil an appropriate
Si.ze-exLfusion cotomn. Such weit-defined, or pur"itied, or highly purified,
enzyme can be obtained
as is knowti in the art and/or described in publications retati g to the
specific enzyrne in question.
Tf3e term "applied togetfier with" (or. used togetfier witti") rrieans that
the additional en-
z.yme may be applied in the same, or in another step of the process of the
iravention. The other
process step may be opstream or dowtist.ream ir3 the paper manufacturing
process, as compared
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to the step in which the Paperma#c(rlg pulp or process water is treated with
lipase and peroxide
source.
tn particoLir emboditnents the additiorlal enzyme is an enzyme which has
protease, xy-
lanase, cuffi7asef oxidoreductase, cellulase, endoglucanase, amylase,
marlrlariase, steryl es-
terase, and/or cholesterol esterase activity. Examples of oxidoreductase
erfzyrnes are enzyrnes
with laccase, and/or peroxidase avivity.
The term "a stepY of a process means at least one step, and it could be one,
two, three,
four, five or even more process steps. Tbus, the lipase and peroxide source
may be appiied in at
[east one process step, and the ciddit#enai enzyme(s) may also be applied iri
at least orle process
step, which may be the same or a different process step as compared to the
step where tile lipase
and peroxide source is used.
The term "enzyme preparationry means a product coniairiirig at least one
lipase erizyme.
In addition to ttle enzymatic activify suatt a preparation preferably
contairls at least one adjuvarit.
Examples of acljfivants, tArhtch ar'e used in erizyrne preparatiorts for the
frapec' and pulp industry:
are buffers, polymers, srirfactarrts and stabilizing agents.
Any enzyme llaving protease, xylanase, cutinase, oxidoreductase, celtulase
endogluca-
nase, arnylase, mannanase, steryl esterase, artdior cholesterol esterase
activity can be used as
additional enzymes iri the use and process of the inventiari. Below some nrrn-
tirniting examples
are listed of such additional etlzymes. The erizyrnes written in capitals are
commercial enzymes
available from Novozymes A/S. Krogshoejvej 36, DK-2880 bagsvaerd, Derimariti.
The activity of
arly of those additional enzymes cari be analyzed using any method knowri iri
the artfor the erl-
Zyrne in queStifJf2, inciUd1t1g ti3e ITlettlods rl'lerF't3fJtled in tiie
references cited.
Exarnpies of cutinases are those eferived from Fltrmicofa insolens (US
5,827t719); from a
strairt of Fusarititn, e.g. F. roseum cufmorum, or partrcularly F. solani pist
(WO 90I09446; WO
94114964, WO 94/03578). The cutirlase may also be derived frorn a strain of
Rhizootonia, e,g. R.
solani, or a strain of Afiternaria, e.g. A. farassicicoia (WO 34103578), or
variants thereof srach as
those described in WO 00/34450, or VVU 01 /92502,
Examples of proteases are the ALCALASE, ESPERASE, SAVINASE, NEUTRASE and
DURAZYM proteases. Other proteases are derived from Nacardsopsis,
AspergiflLts, R17izopus, E3a-
cillcts afcalrspi7flus, B. ceretis, B. r3atto, B. virlgafus, B. rnyco0e, and
subtilisirls from Bacillus. es-
pecially proteases from the species Nocarciiopsis sp, and IVor.arcfiopsr's
dassotivtllei such as those
disclosed in 1l~lo 88i03947> and mutants thereof, e.g. those disclosed ifl WO
91/00345 and EP
415296,
Exarnples of amylases are the BAN, AQUAZYM, TERMAMYL, and AQUAZYM Ultra artly-
lases. An exampte of a xylanase is the PULPZYME HC tlemicellulase. Examples of
endogluca-
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Ãiases are ttie NOVOZYM 693, 342, and 476 erizyrl3e products.
Examples of mannatiases are the TrxcJioderma reesei erido-beta-mannanases
described
in StAblbrarid et ai. J. Biotechnot. 29 (1993), 229-242.
Exaitiptes of steryl esterases, peroxidases, laocases, and cholesterol
esterases are dis-
ctosed in ttie references r'nerÃtioned in the bac;kgrourrd art section
tiereof. i'urttier examples of oxi-
doreductases are the peroxidases and Iacoases disclosed in F-F' 730641; VVO
01/98469; EP
719337; EP 765394; iwP76783G; EP 763115; and EP 788547. In the present
context, vahenever
an oxidoredtrckase enzyme is mentioned that requires or berreRs from the
presence of acceptors,
enhancers, mediators and/or adivaters, such compounds shocÃId be considered to
be itictuded i-f
not already preserit. Example.s of eÃzharrcers and mediators are disclosed in
EP 705327; WQ
98156899~ EP 677102; EP 781328; and EP 707637. Ifdesirec! adisf.inction could
be made by de-
fining an oxidoreductase enzyÃrie system (e.g. a laccase, or a peroxidase
enzyme systern) as the
combination of tti*e enzyme in questiort and its acceptor, and optior3aliy
also an enfiarlcer and/or
mediator for the enzyme in qtÃes#ion.
These are parfictiiar embodiments of the present inventiors: Use of a lipase
and peroxide
source for redrÃc.ing the depcsitio:n of pitch in the paper making praoess. A
process for reducing
depositicn of pitch in the paper making process, wherein the process comprises
treatilig the pulp
arid/or process water with a lipase and peroxide sotirce. Use of a lipase,
peroxide sourGe ars.d or-
gariic acid for reducing the depositiori of pitch in the paper making
prar.ess. A process for reducing
ciepositioÃi of pitch iri the paper r:nakirig process, wherein the process
comprises treating the pulp
aÃid/or process water with a lipa se, a peroxide sooroe and organic acid.
The invefitiarà described and claimed herein is riat to be limited in scope by
the specific
embodiments herein disc#oserl, siÃice these embodiments are intended as
itiustratioris of several
aspects of the invention. Any eqfÃivaient emboriimeiits are intended to be
within the scope of this
inventiort. Indeed, various modifications of the invention in addition to
those shown and described
herein will become apparent to those skilled in the art from the foregoing
description. Such mcÃctÃ-
fcations are also intended to fall vvitbin the scope ofthe appended claÃms, In
the case of conffict,
the present disclosure inoiudiny defitiiiions will casitroi.
Various references are cited hereiri, the disclosures of which are
irtcorporated by refer-
errce in their entireties.
EXAMPLES
ExaQeresinatiori of Kraft pulp pitch by Candida antarcftoa lipase B (CALB)
Dammar resin was obtained from Fluka and used as a model pitch to sirniaÃate
Kraft pulp pitch.
8
CA 02637691 2008-07-18
WO 2007/095575 PCT/US2007/062136
TAED was also cbta#ned froM Fluka. Put 75 mg of Dammar res#ri in a flask and
add 75 mL of pI
water. Add chemicals or enzymes accor-dirig to the canditiQris shown in Table
1. Stir at ambient
temperature overnight. Ttrrbidity ofttre solutions was determined by UV-vis at
600 rirn.
------------- -------------- -- ------- -----
Sampte In Chernicai/Errzyrrte Dose per beaker 640nm
I Ctintrni 0.043
2 CALB 50 rtig 0.222
3 Peraxide 25 mg 0.084
4 CALB aÃid peroxide 50 rrrg/25 Ãng 0.847
Peroxide and TAiwp 25 rng/360 mg 0.501
5
After mixing the samples ev.errÃight, it was observed that the lipase (CAt-B)
and peroxide treated
sample tLrrÃied into milky emulsion whereas the control sample was still as
clear as water with the
resiris deposited either at the bottom ori the wall of the cfthe flask. The
turbidity resr,ilts clearly
showed that a corrsbinat#ori of peroxide wfth lipase could lead to better
emulsificati0r10f dammar
resiri. Peracetic acid gerierated irr sritu by peroxide iand ar bleach
activator (TAED) was also fiairiy
effective, but not as effective as peroxide and lipase combinatiari.
E>cam21e 2. C3eresinatiQri of Kraft pulp pitch by Resir}ase A2X and Resiriase
NT.
Tfie experiment was carried out iri ttte sarr3e rrisraner as ia(ustrateci iri
ExaÃrrpie t except tttat the
flasks were stirred overnigttt at 40"C. The iipsses used in this study were
ResinaseO A2X and
ResinaseO HT (available from Novozymes AfS).
Sampie ID Chemical/Enzyme Dose per beaker 600nm
5 GOr~tr~l 0.104
,.~ ,,,,~....,...._,..V...,m,..,...,..., Resir3asiBO A2X .,,.,.' 50 mg/25
mg0.178.,..v..-.......m_.....,,,,..
8 Resinase@ NT 60 Mg/25 mg 0.219
9 ResinaseO A2X and 50 mg/25 mg 0.535
H2Oy
10 ResiriaseQ HT arid 50 mg/25 ÃTig 10,614
H,Q~
it is euiderlt that both ResinaseJ A2X and ResiriaseCw HT worked to emulsify
the Kraft model
pitch.
~
