U.S. patent application number 11/110861 was filed with the patent office on 2005-11-03 for method for decomposing polyesters containing aromatic moieties, a denier reduction method of fiber, and microorganisms having activity of decomposing the polyester.
This patent application is currently assigned to Kyoto Institute of Technology. Invention is credited to Kimura, Yoshiharu, Oda, Kohei.
Application Number | 20050245722 11/110861 |
Document ID | / |
Family ID | 18108116 |
Filed Date | 2005-11-03 |
United States Patent
Application |
20050245722 |
Kind Code |
A1 |
Oda, Kohei ; et al. |
November 3, 2005 |
Method for decomposing polyesters containing aromatic moieties, a
denier reduction method of fiber, and microorganisms having
activity of decomposing the polyester
Abstract
A polyester containing aromatic moieties is contacted with
microorganisms having the activity of decomposing the polyester to
decompose or reduce it. Preferably, either or both of Trichosporon
FERM BP-6445 or Arthrobacter FERM BP-6444 was contacted with the
polyester to decompose or reduce it. A fiber made of the polyester
or a cloth made of such fiber may be reduced by contacting it with
the microorganisms having the activity of decomposing the
polyester.
Inventors: |
Oda, Kohei; (Izumi City,
JP) ; Kimura, Yoshiharu; (Ohmihachiman City,
JP) |
Correspondence
Address: |
VENABLE LLP
P.O. BOX 34385
WASHINGTON
DC
20045-9998
US
|
Assignee: |
Kyoto Institute of
Technology
Matsugasaki Kyoto City
JP
|
Family ID: |
18108116 |
Appl. No.: |
11/110861 |
Filed: |
April 21, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11110861 |
Apr 21, 2005 |
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10090155 |
Mar 5, 2002 |
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6939706 |
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10090155 |
Mar 5, 2002 |
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09353445 |
Jul 14, 1999 |
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6376213 |
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11110861 |
Apr 21, 2005 |
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10090160 |
Mar 5, 2002 |
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6878537 |
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Current U.S.
Class: |
528/296 |
Current CPC
Class: |
B29C 44/581 20130101;
C12N 1/145 20210501; B29C 44/38 20130101; D06M 16/003 20130101;
Y10S 435/83 20130101; C12R 2001/06 20210501; C12P 7/625 20130101;
C12R 2001/645 20210501; D06M 2101/32 20130101; D06M 16/00 20130101;
C12N 1/205 20210501 |
Class at
Publication: |
528/296 |
International
Class: |
C08G 063/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 10, 1998 |
JP |
10-319,251 |
Claims
1-13. (canceled)
14. A reduced fiber produced by a denier reduction method
comprising contacting a microorganism having activity for
decomposing a polyester containing an aromatic moiety, with the
fiber to reduce the denier of the fiber.
15. A reduced fiber produced by a denier reduction method as
claimed in claim 14 wherein the fiber is reduced by contacting it
with Trichosporon FERM BP-6445.
16. A reduced fiber produced by the denier reduction method as
claimed in claim 14 wherein the fiber is reduced by contacting it
with Arthrobacter FERM BP-6444.
17. A reduced cloth produced by the denier reduction method as
claimed in claim 14 wherein a cloth made of the fiber is contacted
with the microorganism to reduce the weight of the cloth.
18-23. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates to a method for decomposing
polyesters containing aromatic moieties, a method for reducing a
fiber made of such polyesters, and microorganisms capable of
decomposing fibers made of such polyesters.
[0003] 2. Description of the Related Art
[0004] A law for recycling a container and wrapping was enforced in
April, 1997 for reducing such wastes and the resulting
environmental pollution, which has been attracting public
attention. A grace period of 3 years is provided for a container
and wrapping made of a plastic material, which will be under the
law, necessitating a high cost for the recycling, from April, 2000.
Polyethylene terephthalate, universally used for a container of
soft drink and seasoning, also will be under the law. Manufacturers
try to collect and recycle such container.
[0005] However, polyesters containing aromatic moieties, such as
polyethylene terephtalate or polybutylene terephthalate, are
finally treated by reclamation or burning-up. The burning-up
process inevitably produces harmful wastes and the reclamation may
produce-floating wastes on water, both leading to further
environmental pollution.
[0006] Therefore, a container or wrapping material made of a
polymer containing aromatic moieties, and clothes and-ornaments
made of the polyester discharged in an apparel industry will
require high costs for their recycling and should finally be
treated by reclamation or burning-up. A solution for treating such
materials has been demanded.
SUMMARY OF THE INVENTION
[0007] An object of the invention is to provide a method for
treating a material or fiber made of a polyester containing
aromatic moieties, with adverse effects on environment
substantially reduced.
[0008] Another object of the invention is to apply such treating
method to denier-reduction process of fiber.
[0009] The present invention provides a method for decomposing
polyesters containing aromatic moieties, the method comprising:
[0010] contacting a microorganism having an activity of decomposing
polyesters containing aromatic moieties with the polyester to
decompose it.
[0011] The inventors succeeded in decomposing a polyester
containing aromatic moieties by means of microorganisms for the
first time in the globe. Although aliphatic polyesters have been
known to be biodegradable, it has never been known that the
polyesters containing aromatic moieties are susceptible to
decomposition by microorganisms. As a result, the invention may
decompose and degrade such aromatic polyesters without
environmental pollution, then decomposition products with low
molecular weights may be returned into a substance-recycling system
in natural environment.
[0012] The inventive method for decomposing polyesters containing
aromatic moieties may be applied to a container, a wrapping
material, as well as a fiber and cloth, each made of such
polyesters. When the wastes containing the polyesters are subjected
to composts, microorganisms included in the composts rapidly
decompose the polyesters into nontoxic substances. Alternatively,
when the wastes containing the polyesters are reclaimed,
microorganisms may be included in wastes to decompose the
polyesters. Such polyester wastes, contained in the composts or the
reclaimed wastes, may be partly or wholly decomposed.
[0013] An effective treatment has not been found yet to treat so
called a pet-bottle (a bottle made of polyethylene terephthalate).
The invention provides a method for treating such bottle without
leaving further wastes in natural environment.
[0014] The other treating methods, such as reclamation and
burning-up, may produce harmful substances. The inventive
microorganisms capable of decomposing the polyesters may survive
for a long time, even when utilizing the polyesters as a sole
carbon source, thereby probably alleviating the possibility of
producing harmful substances.
[0015] The inventors also succeeded in applying the inventive
decomposition method for denier reduction process of the surface of
fibers made of polyesters containing aromatic moieties. The
inventive reducing method produces no decomposition residue, which
has been inevitably produced in the previous caustic (denier)
reduction method of a fiber, thereby providing technique suitable
for environment. The inventive reduction method is also useful for
obtaining a fiber with better fitting and appearance. For example,
a cotton fiber has been treated to improve its fitting and
appearance by means of cellulase derived from microorganisms. The
inventive denier reduction method may also produce a fiber and
cloth made of the polyesters with improved fitting and appearance.
Moreover, the thus obtained fiber has small depressions, hollows
and ditches or grooves on the surface formed during the reduction
process, thus facilitating its dyeing.
[0016] The inventors have confirmed the activity of decomposing a
polyester containing aromatic moieties, in the following
microorganisms.
[0017] (1) Trichosporon FERM BP-6445
[0018] (2) Arthrobacter FERM BP-6444
[0019] A polyester containing an aromatic moiety is a polyester
produced by polymerizing monomers, at least one of the monomers
being an aromatic compound. Such polyester is not particularly
limited. However, such polyester may preferably be a polyalkylene
phthalate, isophthalate or terephthalate, more preferably be
polyethylene terephthalate, polypropylene terephtlhalate, or
polybutylene terephthalate, and most preferably be polyethylene
terephthalate or polybutylene terephthalate. The polyester may be a
homopolymer of an aromatic compound, or a copolymer of aromatic
compounds, or a copolymer of an aromatic compound and an aliphatic
compound. The aromatic compound is not limited, and preferably be
alkylene terephthalate such as ethylene terephthalate, propylene
terephthalate and butylene terephthalate.
[0020] These and other objects, features and advantages of the
invention will be appreciated upon reading the following
description of the invention when taken in conjunction with the
attached drawings, with the understanding that some modifications,
variations and changes of the same could be made by the skilled
person in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a better understanding of the invention, reference is
made to the attached drawings, wherein:
[0022] FIG. 1 is a photograph showing the surface of a fiber made
of polyethylene terephthalate, taken by an electron microscope (at
a magnitude of 3000), after treating it with a yeast-like
microorganism having the activity of decomposing a polyester
containing aromatic moiety for 30 days,
[0023] FIG. 2 is another photograph showing the surface of a fiber
made of polyethylene terephthalate, taken by an electron microscope
(at a magnitude of 3000), after treating it with the same
yeast-like microorganism as FIG. 1 for 30 days,
[0024] FIG. 3 is a photograph showing the surface of a fiber made
of polyethylene terephthalate, taken by an electron microscope (at
a magnitude of 3000), after treating it with a bacterium having the
activity of decomposing a polyester containing aromatic moiety for
55 days,
[0025] FIG. 4 is another photograph showing the surface of a fiber
made of polyethylene terephthalate, taken by an electron microscope
(at a magnitude of 3000), after treating it with the same bacterium
as FIG. 3 for 55 days,
[0026] FIG. 5 is a photograph showing the yeast-like microorganism,
taken by an optical microscope at a magnitude of 1500,
[0027] FIG. 6 is a photograph showing hyphae and oidia (at a
magnitude of 470) formed after cultivating the yeast-like
microorganism of FIG. 5 on a corn meal agar plate at 25.degree. C.
for 3 days,
[0028] FIG. 7 is a photograph showing the bacterium having the
activity of decomposing a polyester containing an aromatic moiety,
taken by an optical microscope at a magnitude of 1500,
[0029] FIG. 8 is a photograph showing the bacterium of FIG. 7 after
cultivating it for 8 hours, and
[0030] FIG. 9 is a photograph showing the bacterium of FIG. 7 after
cultivating it for 72 hours.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] (Screening of Microorganisms Capable of Decomposing a
Polyester Containing an Aromatic Moiety)
[0032] The inventors found a method of cultivation for screening a
micro-organism capable of decomposing a polyester containing
aromatic moieties, such as polyethylene terephthalate. Polyethylene
terephthalate is insoluble in water and usually has a crystalline
structure. The inventor therefore added fibers, made of an
amorphous or non-crystalline polyethylene terephthalate, in a
medium having the-following composition. Fibers were used for
facilitating the judgement on whether the decomposition took place
or not, in other words, the screening of a microorganism capable of
decomposing the polyester. Moreover, a medium containing polyesters
having aromatic moieties as a sole carbon source was used for
enrichment culture.
1 Used Medium yeast extract 0.1% ammonium sulfate 0.2% salt mixture
FeSO.sub.4.7H.sub.2O 0.001% CuSO.sub.4.5H.sub.2O 0.0001%
ZnSO.sub.4.7H.sub.2O 0.0001% MgSO.sub.4.7H.sub.2O 0.0001%
[0033] The used medium had unadjusted pH. 7 ml of the medium was
contained in each tube, which was put into an autoclave and then
sterilized at 120.degree. C. for 15 minutes. Thereafter fibers made
of amorphous polyethylene terephthalate were added into each tube
so that its content is made 0.2 percent. Each fiber has a diameter
of 120 micrometer, a length of 5 centimeter, 12 fibers were added
into each tube.
[0034] 400 soil samples collected from many places in Japan were
screened. A spoonful (spertel) of each soil sample was added into
each medium and it was cultured at 25 to 30.degree. C. for 1 week
to select soil sample with the growing of a microorganism confirmed
(first stage screening). Each soil sample was then subjected to
subculture with its medium replaced every two weeks to perform
enrichment culture for two months. At the end of second month,
fibers made of polyethylene terephthalate were drawn from each
culture medium to measure their tensile strengths using
Tensilon/JTM-4L (Toyo Measuring Instruments Co. Ltd. 50 mm /min).
When the tensile strength of the treated fiber is considerably
reduced compared with that of an untreated fiber (blank), such
fiber is further observed by means of a scanning electron
microscope (Hitachi S-800). These results of the tensile strength
and surface observation were considered to judge whether it is
decomposition-positive or negative (second stage screening).
[0035] (Isolation of Microorganisms and its Activity of Decomposing
a Polyester Containing Aromatic Moieties)
[0036] Two samples were selected from several soil samples in which
the tensile strengths of the fibers were reduced. A microorganism
was isolated from each of the selected two samples as a single
colony. Each micro-organism has the activity of decomposing a
polyester containing aromatic moieties. A yeast-like microorganism
was isolated from one sample and a bacterium was isolated from
another. The ratio of the tensile strength of the treated fiber to
that of the untreated fiber (blank) was reduced to 60 percent after
30 days, in the sample from which the yeast-like microorganism was
isolated. The ratio of the tensile strength of the treated fiber to
that of the untreated fiber (blank) was reduced to 92 percent after
30 days and 51 percent after 55 days, in the sample from which the
bacterium was isolated.
[0037] FIGS. 1 and 2 show photographs of the surface of the fiber
treated with the yeast-like microorganism, taken by an scanning
electron microscope (at a magnitude of 3000). As shown in the FIGS.
1 and 2, many circular-shaped craters or depressions were observed
on the surface of the fiber.
[0038] FIGS. 3 and 4 show photographs of the surface of the fiber
treated with the bacterium by a scanning electron microscope (at a
magnitude of 3000).
[0039] As shown in the FIGS. 3 and 4, many eroded regions were
formed and each eroded region tends to elongate in the longitudinal
direction of the fiber to form small ditch or groove. Therefore,
the yeast-like microorganism and bacterium may decompose the fiber
to form eroded regions with characteristic patterns and morphology
different form each other. Therefore, the fiber may be more
effectively decomposed or reduced by contacting both of the
yeast-like microorganism and bacterium together with the fiber.
[0040] (Identification of the Yeast-like Microorganism)
[0041] This microorganism belongs to Trichosporon. Its
international deposit number is Trichosporon FERM BP-6445.
Trichosporon is an incomplete yeast belonging to basidiomycetes
which forms hyphae and oidia. The known main sources of
Trichosporon are foods, intestines including that of a human,
water, waste water, trees, saps or the like (reference: Kreger-van
Rij, N. J. W. .left brkt-top.The Yeasts, 1984, Elsevier Science
Publishers B. V. Barnett, J. A., Payne, R. W. and Yarrow. D. .left
brkt-top.Yeasts: Characteristics and identification.right brkt-bot.
Second edition, Cambridge University Press)
2 Morphology of vegetative cell spherical, ellipsoidal, cylindrical
Form of multiplication multipolar budding, forming oidia Liquid
culture precipitation and coating were observed (25.degree. C., 3
days) Pseudomycelia observed (25.degree. C., 3 days) Hyphae
observed (corn meal agar plate culture, 25.degree. C., 3 days)
Oidia observed (corn meal agar plate culture, 25.degree. C., 3
days) Ascospores not observed on Adams, Gorodkowa, malt, YM, V-8
and potato dextrose media) Fermentation of glucose negative
Assimilation of inositol positive Assimilation of nitrate negative
Decomposition of urea negative (not typical form) Coloration of DBB
positive Xylose in cell wall positive
[0042] FIG. 5 shows a photograph of the yeast-like microorganism,
taken by an optical microscope (at a magnitude of 1500). FIG. 6 is
a photograph showing its hyphae and oidia observed after
cultivating the microorganism on a corn meal agar plate medium at
25.degree. C. for 3 days, taken by an optical microscope (at a
magnitude of 470).
[0043] (Identification of the Bacterium)
[0044] (Arthrobacter FERM BP-6444)
[0045] The bacterium was identified to belong to Arthrobacter,
based on its morphology, physiological properties, celluler
components, and a GC content: (Sneath P. H. A., Mair, N. S., Sharpe
M. E. and Holt J. G. .left brkt-top.Bergey's Manual of Systematic
Bacteriology.right brkt-bot. Vol. 2, 1986, Wiliams and Wilkins:
Holt J. G., Krieg N. R., Sneath P. H. A., Stanley, J. T. and
Wiliams, S. T. .left brkt-top.Bergey's Manual of Determinative
Bacteriology.right brkt-bot. ninth edition, 1994, Wiliams and
Wilkins).
[0046] Arthrobacter belongs to an asporogenic gram-positive rod
bacteria showing polymorphism.
3 Morphology polymorphic rod bacteria Gram stain positive Spores
negative Motility positive Relation to oxygen aerobic Oxidase
negative Catalase positive OF negative Resistance to acidity
negative Color of colony not forming characteristic pigments Rod
coccus cycle positive Elongation of peripheral negative cells in
colony Cell wall Diamino acid lysine Acyl-type acetyl-type
Arabino-galactan polymer negative (assumed using acidic hydrolysis
products of the whole cell) Main quinone series MK-9 (H2) GC
content in the DNA 65 (mole percent: measured by HPLC method)
[0047] FIG. 7 is a photograph showing the bacterium, taken by an
optical microscope (at a magnitude of 1500). FIG. 8 shows the
bacterium after cultivating it in EYGA medium at 30.degree. C. for
8 hours, and FIG. 9 after 72 hours.
[0048] (Denier-reduction Treatment of a Cloth Made of
Polyester-fibers Containing Aromatic Moieties)
[0049] Cloths made of polyethylene terephthalate were reduced by
contacting them with the yeast-like microorganism or bacterium,
using the above described medium samples used for screening.
[0050] In experiment A, a cloth made of crystalline polyethylene
terephthalate fibers, with a dimension of 18 mm.times.18 mm and a
weight of 2.083 gram, was dipped in the above medium, to which the
yeast-like microorganism was inoculated. Then, it was cultured for
55 days at 30.degree. C., with its medium replaced every 2 weeks.
After the cultivation, the cloth was taken out from the liquid
culture and weighed. Experiments B and C were also performed,
except that the bacterium was added instead of the yeast-like
microorganism in the experiment B and both were added in the
experiment C.
[0051] As a result, the weight of the cloth was reduced to 1.753
gram in the experiment A, reducing 15.8 percent of its original
weight. The weight of the cloth was reduced to 1.751 gram in the
experiment B, reducing 15.9 percent of its original weight. The
weight of the cloth was reduced to 1.729 gram in the experiment C,
reducing 17.0 percent of its original weight. Moreover, fitting and
appearance were improved when observed by eyes, and the handling
was considerably changed.
* * * * *