WO1999029885A1

WO1999029885A1 - Degradation of biodegradable polymers

Info

Publication number: WO1999029885A1
Application number: PCT/EP1998/007610
Authority: WO
Inventors: Rainhard Koch; Simone Wiegand
Original assignee: Bayer Aktiengesellschaft
Priority date: 1997-12-05
Filing date: 1998-11-25
Publication date: 1999-06-17
Also published as: AU1875599A; DE19754063A1

Abstract

The invention relates to the degradation of moulded bodies, flat materials, coatings, adhesive bonds or foams which consist of biodegradable polymers using pure cultures of micro-organisms and the enzymes produced by these micro-organisms. The invention relates to the microbial degradation of polyester amides and polyester urethanes containing urea groups in particular.

Description

Degradation of biodegradable polymers

The invention relates to the degradation of moldings, fabrics, coatings, adhesions or foams from biodegradable polymers with pure cultures of microorganisms and the enzymes which are formed by these microorganisms.

In particular, it relates to the degradation of polyester amides and polyester urethanes containing urea groups.

Fully biodegradable and compostable materials are becoming increasingly important. A large number of such polymers have been developed in recent years with the aim of having a plastic available which can be recycled by composting. At the same time, various regulations and standards have been issued which regulate the access of such materials to composting (LAGA Leaflet M 10; Biowaste and Compost Ordinance) or which can demonstrate harmless compostability (DEN 54900). Under biodegradation in this

Always understood the context that the so-called materials are metabolized in the presence of microorganisms to CO ₂ and biomass.

In most of the cases investigated to date, the biodegradation is demonstrated by incubating the test material with a mixed culture of microorganisms and by demonstrating the degradation by converting the polymer to CO ₂ .

Polyester amides are generally known to be subject to biodegradation (J. Appl. Polym. Sei., 1979, S 1701-1711, US Pat. 4343931, US Pat. 4529792, Jap. Pat. 79119593, Jap. Pat. 79119594, EP-A 641817). In the cases shown, degradation with mixed cultures is demonstrated. The biodegradation of polyester amides by pure cultures has not yet been described.

Polyester urethanes containing urea groups are also known to be completely biodegradable. The speed and scope of the

Degradation depends on the monomer composition (DE-A 195 17 185). Are further

Bacteria have been isolated that grow as pure culture on the investigated polymers can. These bacteria are, for example, a strain of the Pseudomonas fluorescence type.

The enzymatic attack of individual bonds by a proteolytic enzyme in such polymers has been described (G. T. Howard, R. C. Blake, ASM General

Meeting 1996, Abstracts S 430).

It has been found that biodegradable polyesteramides and polyurethanes containing urea groups can be degraded by selected bacteria. Another new feature is that the bacteria mentioned here have the property of being biodegradable

To break down polyurethanes containing polyesteramides and urea groups. Bacteria that can grow on polyester-containing degradable polymers are known from the following groups:

Penicillium spp 14-1 and 26-1 (Tokiwa et al., 1974, J Ferment Technol 52: 393; Tokiwa et al., 1976, J Ferment. Technol. 54: 603), Acidovorax avenae susp avenae, Paecilomyces marquandii (Mergaert , J .; Swings, I, 1996, J. Ind. Microbiol. Biotechnol., 17 (5/6), 463-469), Aspergillus ßimigatus, Aspergillus terreus, Penicillium olscnii and Fusarium semitectum (Kang et al., 1996, Pollimo, 20 (6), 960-970), Alternaria sp. (Tsuju et al., 1978, Hakko Kogaku Kaishi, 56 (6), 799-801), Pseudomonas testosteroni ATCC 17510,

Alcaligene paradoxus ATCC17718 (Tanaka et al., 1976, Nippon Nogei Kagaku Kaishi, 50 (9), 431-6).

Thermophilic bacteria which are able to degrade degradable polyester amides or polyester urethanes containing urea groups at 60 ° C. have so far not been known. Furthermore, no bacteria are known which are able to grow on such plastics in the presence of increased salt concentrations.

The invention relates to a process for the degradation of biodegradable polymers, in particular polyester amides and urea groups

Polyester urethanes from strains of the bacterial species Paenibaccillus lautus, Bacillus pumilus, Aeromicrobium spec, Thermobispora bispora, Bacillus spec. RNA group V, Brevibacillus spec. as well as the esterases, lipases or oligoamidases to be obtained from them, the biodegradable polymers according to the invention being introduced into an aqueous nutrient solution and inoculated with a pure culture or a mixed culture of the bacterial species mentioned.

For the biodegradation of the degradable polyester amides and urea-containing polyester urethanes, pure cultures of the following microorganisms come into question: Paenibaccillus lautus, Bacillus pumilus, Aeromicrobium spec, Thermobispora bispora, Bacillus spec. RNA group V, Brevibacillus spec. Degradation is preferably carried out with the following microorganisms: Paenibacillus lautus (DSM 11870), Bacillus pumilus (DSM 11871), Thermobispora bispora (DSM 11873), Aeromocrobium spec. (DSM 11872). These strains are deposited with the German Collection of Microorganisms and Cell Cultures GmbH (DSMZ), Braunschweig, Mascheroder Weg lb. The filing date is November 24, 1997.

The invention also relates to the deposited microorganisms, and to their mutants and variants, which still have the ability to degrade the polymers mentioned here.

The mutants and variants of the deposited microorganisms according to the invention are understood in particular to be bacteria which have a homology of at least 70%, preferably at least 80% and very particularly preferably at least 90% to the deposited microorganisms at the nucleic acid level.

Suitable biodegradable and compostable polymers are aliphatic or partially aromatic polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, which may also have urea groups, aliphatic-aromatic polyester carbonates and aliphatic or partially aromatic polyester amides. Polyester amides and polyester urethanes containing urea groups are preferred. The following polymers are suitable:

Aliphatic or partially aromatic polyester

A) linear bifunctional alcohols, preferably C ₂ -C 1 -alkyldiols, such as ethanediol, butanediol, hexanediol, preferably butanediol, and / or optionally cycloaliphatic bifunctional alcohols such as, for example, cyclohexanedimethanol and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ -Cι _2- alkyldiols, such as neopentyl glycol, and additionally optionally small amounts of higher-functional alcohols, preferably C ₃ -C ₂ -alkyl polyols, such as 1,2,3-propanetriol or trimethylolpropane, and from aliphatic bifunctional acids, preferably C ₂ -Cι _2- alkyl dicarboxylic acids, such as, for example and preferably, succinic acid or adipic acid, and / or optionally aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and, if appropriate, small amounts of higher functional acids such as, for example Trimellitic acid or

B) from acid and alcohol functionalized building blocks, preferably with 2 to 12

C atoms in the alkyl chain, for example hydroxybutyric acid or hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide,

or a mixture or a copolymer of A and B,

the aromatic acids making up no more than 50% by weight, based on all acids.

The acids can also be in the form of derivatives such as acid chlorides or

Esters are used; Aliphatic or partially aromatic polyester urethanes, which can also have urea groups

C) an ester portion from bifunctional alcohols, preferably C ₂ -C ₂ alkyldiols such as ethanediol, butanediol, hexanediol, preferably butanediol, and / or cycloaliphatic bifunctional or polycyclic aliphatic alcohols such as cyclohexanedimethanol and / or optionally smaller amounts branched bifunctional alcohols, preferably C ₃ -C ₂ alkyldiols, such as neopentyl glycol, and in addition, if appropriate, small amounts of higher functional alcohols, preferably

C ₃ -C-alkyl polyols, such as 1,2,3-propanetriol or trimethylol propane, and from aliphatic bifunctional acids, preferably C ₂ -C π-alkyl dicarboxylic acids, such as and preferably succinic acid or adipic acid, and / or aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and additionally, if appropriate, small amounts of higher functional acids such as, for example, trimellitic acid or

D) from acid and alcohol functionalized building blocks, preferably with 2 to 12 carbon atoms, for example hydroxybutyric acid or hydroxyvaleric acid or

Lactic acid, or its derivatives, for example ε-caprolactone or dilactide,

or a mixture or a copolymer of C and D, and

E) from the reaction product of C and / or D with aliphatic and / or cycloaliphatic bifunctional and additionally optionally higher functional isocyanates, preferably with 1 to 12 C atoms or 5 to 8 C atoms in the case of cycloaliphatic isocyanates, for example tetramethylene diisocyanate, hexamethylene diisocyanate , Isophorone diisocyanate, optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher functional alcohols, preferably C ₃ -C 8 -alkyl polyols or 5-8 C atoms in the case of cycloaliphatic alcohols, for example ethane diol, hexanediol, butanediol, cyclohexanedimethanol, and / or optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher functional dialkylamines or aminoalcohols with preferably 2 to 12 carbon atoms in the alkyl chain, such as, for example, ethylenediamine or aminoethanol and / or optionally further modified amines or alcohols such as, for example, ethylenediaminethanesulfonic acid, as the free acid or salt,

wherein the ester fraction C) and / or D) is at least 75% by weight, based on the sum of C), D) and E);

Aliphatic-aromatic polyester carbonates

F) an ester fraction from linear bifunctional alcohols, preferably C ₂ -C ₁₂ -alkyldiols such as, for example, ethanediol, butanediol, hexanediol, preferably butanediol and / or cycloaliphatic bifunctional alcohols, such as, for example, cyclohexanedimethanol and / or optionally small amounts of branched bifunctional alcohols, preferably with 3 up to 12 C atoms in the alkyl chain, such as neopentyl glycol, and additionally, if appropriate, small amounts of higher-functional alcohols, preferably with 3 to 12 C atoms in the alkyl chain, such as 1,2,3-propanetriol or trimethylolpropane, and from linear and / or cycloaliphatic bifunctional and additionally optionally small amounts of higher functional acids, preferably with 2 to 12 carbon atoms in the alkyl chain, preferably adipic acid,

or

G) from acid and alcohol functionalized building blocks, preferably with 2 to 12 carbon atoms in the alkyl chain, for example hydroxybutyric acid or hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide, or a mixture or a copolymer of F) and G) and

H) a carbonate component which was produced from aromatic bifunctional phenols, preferably bisphenol-A, and carbonate donors, for example phosgene.

The ester fraction F) and / or G) must be at least 70% by weight, based on the sum of F), G) and H);

Aliphatic or partially aromatic polyester amides

I) an ester fraction from linear or aromatic alcohols, preferably

C ₂ -C ₂ alkyldiols, such as ethanediol, butanediol, hexanediol, preferably butanediol and / or cycloaliphatic bifunctional alcohols such as cyclohexanedimethanol and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ -C ₂ alkyldiols, such as Neopentylglycol, and additionally optionally small amounts of higher functional alcohols, preferably C ₃ -C 8 alkyl polyols, such as 1,2,3-propanetriol or trimethylolpropane, and from linear and / or cycloaliphatic bifunctional, and additionally optionally small amounts of higher functional acids, preferably with 2 to 12 carbon atoms in the alkyl chain or phenyl or naphthyl rings, preferably adipic acid, or

K) from acid- and alcohol-functionalized building blocks, preferably with 2 to 12 carbon atoms in the carbon chain, for example hydroxybutyric acid or hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide,

or a mixture or a copolymer of I) and K) and L) an amide fraction of linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional amines with preferably 1 to 12 C atoms in the alkyl chain or C ₅ or Cβ cycloaliphatic bifunctional amines and additionally optionally small amounts of higher functional groups Amines, among the amines preferably isophoronediamine and particularly preferably hexamethylene diamine, and from linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional and additionally optionally small amounts of higher functional acids, preferably with 2 to 12 carbon atoms in the alkyl chain, preferably adipic acid, or

M) from an amide portion of acid and amine functionalized cycloaliphatic building blocks, preferably with 4 to 20 carbon atoms in the cycloaliphatic chain, preferably ω-laurolactam and particularly preferably ε-caprolactam,

or a mixture of L) and M) as an amide component.

The ester content A) and / or B) must be at least 30% by weight, based on the sum of I), K), L) and M).

As alcohol component, it is also possible in part or in whole to use monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights (weight average) of up to 4,000, preferably up to 1,000, instead of the diols.

All degradable polyester urethanes, polyesters, polyester carbonates and polyester amides have a molecular weight of at least 10,000 g / mol and generally have a statistical distribution of the starting materials in the polymer. In the case of a typical polymer structure, possibly from C) and D) and from E), a completely statistical distribution of the monomer units is not always to be expected. All biodegradable polyester urethanes, polyesters, polyester carbonates and Polyesteramides, preferably polyester urethanes, can be present as a substance, solution or dispersion, preferably as a dispersion in water.

The biodegradable polyester urethanes, polyesters, polyester carbonates and polyester amides mentioned here can be equipped with fillers and reinforcing materials and / or with processing aids such as, for example, nucleation aids, mold release agents or stabilizers, it being important to ensure that the biodegradability is not impaired or the remaining ones Substances in terms of further treatment (eg wastewater treatment) are harmless.

Suitable fillers and reinforcing materials can be minerals such as kaolin, chalk, gypsum, lime or talc or natural substances such as starch or modified starch, cellulose or cellulose derivatives or cellulose products, wood flour or natural fibers such as hemp, flax, rapeseed or ramie.

The biodegradable polyester urethanes, polyester carbonates and polyester amides mentioned here can be mixed with each other and also with other blend partners, whereby it must be ensured that the remaining substances are harmless in terms of further treatment (e.g. wastewater treatment). Other biodegradable or non-biodegradable can be used as additional blend partners

Polymers are used.

For the biodegradation of the biodegradable polymers mentioned here, they are introduced into an aqueous nutrient solution and inoculated with a pure culture or a mixed culture of the microorganisms. The following microorganisms can be used: Paenibaccillus lautus, Bacillus pumilus, Aeromocrobium spec, Thermobiψora bispora, Bacillus spec. RNA group V, Brevibacillus spec. Degradation is preferably carried out with the following microorganisms: Paenibaccillus lautus (DSMZ 11870), Bacillus pumilus (DSM 11871), Aeromicrobium spec. (DSM 11872) and Thermobispora bispora (DSM 11873). The degradation of the polymers takes place in an aqueous solution

Nutrient salts are added and which can be aerated. The nutrient solution consists, for example, of the following components (per liter): K ₂ HPO ₄ , 3.5 g; NaH ₂ PO x 2 H ₂ O, 3.5 g; NHtNOs, 0.5 g; MgSO ₄ x 7 H ₂ O, 0.2 g; Trace element solution 1.0 ml (Hormann and Andreesen, 1989, Ach. Microbiol., 153, 50-59); Vitamin solution, 1.0 ml (Pfenning, N., Lippert, D., 1966, Arch. Mikrobiol. 55: 245-256); Yeast extract, 0.05 g; CaCl ₂ x 2 H ₂ O, 0.05 g. The pH was adjusted to 7.0 with 5 M KOH. The nutrient solution may have been sterilized beforehand.

The degradation can be carried out at temperatures between 15 and 70, preferably at temperatures between 25 and 60 and particularly preferably at 30-50 ° C. The degradation can be carried out at a pH between pH 4.0 and 9.0, preferably at pH values between 5.0 and 8.0 and particularly preferably at pH 6.0-7.0.

A generally known nutrient solution can be used (Schlegel, Allgemeine Mikrobiologie, Thieme 1992).

The above process is characterized in that the microorganisms during the

Incubation grow while degrading the polymer.

Another method according to the invention is characterized in that the bacteria according to the invention are cultivated before the treatment of the biodegradable polymer. The biodegradable polymers are then added to this solution. The microorganisms according to the invention can be grown in the nutrient solution described above.

Another method according to the invention is characterized in that the microorganisms on the polymer, oligomers or monomers are grown in an aqueous nutrient solution in order to enrich, purify or concentrate the enzymes formed from the bacterial culture in order to use the latter for enzymatic polymer degradation. The methods described in the literature for growing the microorganisms and for enriching, purifying or concentrating enzymes can be used. Another method according to the invention is characterized in that the genes of the enzymes which are able to degrade the polymers are isolated from the bacteria according to the invention, are transferred to other microorganisms and the polymer-degrading enzymes are then produced in these microorganisms Methods for cloning genes and for expression of proteins are used

The process can be carried out in various ways

The polymer is added to the aqueous nutrient solution inoculated with bacteria. The biodegradable polymer can be added as a film, film or granulate. Shaped bodies can be added as a whole or crushed. Coated or bonded materials or materials in which coatings have been applied or created with biodegradable polymers , such as paper or cardboard and coated paper or coated cardboard, can be added as a whole or crushed to the nutrient solution containing the bacteria according to the invention

Furthermore, the aqueous nutrient solution containing bacteria can be applied or sprayed onto the coating to be broken down or the molded body to be broken down

The described method of microbial degradation of biodegradable polymers (= BAP) and blends made therefrom can be used according to the invention, for example

Inclusion of chemicals, active substances, hormones, auxiliaries, enzymes, microorganisms, plant seeds in BAP (e.g. capsules and microcapsules) and their targeted release through the addition of enzymes Use of BAP as an adhesive or binder to produce composite materials or molded parts from non-moldable materials with the aim of dissolving them again by adding a solution containing bacteria.

- Use of BAP for the production of polymer composites such as

Wood composites for formwork (e.g. building formwork) with the aim of dissolving them by adding a solution containing bacteria or accelerating their detachability

- Use of BAP for coating, gluing or gluing cardboard or

Paper with the aim of microbially degrading and removing BAP. This includes in particular the recycling of coated and / or sized paper, laminating foils or blister packs. This also includes blends made from BAP and non-degradable polymers, which can be removed or dissolved by the microbial treatment. This also includes the coating of cardboard or paper

BAP with the aim of removing printing inks that are difficult to remove (e.g. those that can be crosslinked with UV) with the help of microorganisms in a deinking process.

- Use BAP to glue or coat cardboard or paper with other plastics, lacquers or metallic materials, especially aluminum, with the ZieL BAP microbially and thus remove the other plastics, lacquers or metals in order to recycle them if necessary. The following plastics or lacquers are, inter alia, according to the invention: polyesters, polyamides, polyurethanes, polyolefins, in particular polyethylene and polypropylene, polyacrylates, elastomers such as rubber and its derivatives, polyvinyl alcohol, polyvinyl acetate, cellulose esters, acrylonitrile-containing styrene-butadiene polymers and melanin resins. This includes in particular the recycling of coated paper, laminating films or blister packs. Use of BAP as a binder for applying microcapsules to carbonless carbonless papers with the aim of selectively removing the binder by selected bacteria in order to recycle the paper.

Use of moldings, flat structures, bonds, coatings or foams made of BAP with the aim of breaking them down by pretreating them with selected bacteria. This particularly includes liquefaction with the aim of disposing of the BAP after use as waste via a sewage treatment plant or to reduce the volume of the waste.

Manufacture of moldings, fabrics, foams or coatings that can be made specifically porous by adding suitable enzymes.

- Production of fibers, fabrics, textiles made of BAP, which can be dissolved or reduced in volume by the use of the bacteria according to the invention.

Use of selected bacteria to break down BAP with the aim of producing aqueous dispersions from it.

Selective removal of coatings, coatings, covers or varnishes from BAP with the help of selected microorganisms.

- Production of oligomers from BAP with the help of bacteria.

Manufacture of fabrics, moldings, foams or coatings that can contain chemicals, active ingredients, auxiliaries, enzymes, microorganisms or plant seeds in order to apply them and then release them through bacterial degradation. Production of packaging from BAP of all kinds with the aim of treating the packaged product and releasing it after the treatment by adding bacteria. This applies in particular to the collection of food residues or other goods in films made from BAP with the aim of sterilizing them, storing them sterile and then releasing them again by adding microorganisms.

Use of BAP for the production of printing inks with the aim of producing a bacterially resolvable and / or detachable ink for a bacterial deinking process.

- Use of BAP for packaging active substances or toxic compounds, in particular pesticides, with the aim of producing a bacterially dissolvable packaging or a bacterially dissolvable inlay that enables the repackaging to be recycled without harmful substances.

- Use of BAP to collect waste, in particular faeces, with the aim of using bacteria to dissolve the packaging after collection in order to release and / or dispose of the packaging.

Use of the BAP in combination with other materials or as their coating (e.g. metals or non-degradable plastics) with the aim of bacterially degrading the BAP after use in order to recover the other materials. This applies in particular to the recycling of electronic components.

- Use of a combination of BAP and microorganisms with the aim of treating the BAP with bacteria in order to accelerate their biodegradability in a composting process or an anaerobic treatment process. Examples

1. Granules of polyester amide from 60% by weight of caprolactam and 40% by weight of ester from adipic acid and butanediol, randomly copolycondensed with a relative solution viscosity of 2.5, measured on a 1% by weight solution in meta-

Cresol at 20 ° C is placed in a solid nutrient medium. To create the solid medium, the nutrient solution described above was [from the following components (per liter): K ₂ HPO, 3.5 g; NaH PO ₄ x 2 HO, 3.5 g; NH4NO ₃ , 0.5 g; MgSO ₄ x 7 H ₂ O, 0.2 g; Trace element solution 1.0 ml (Hormann and Andreesen, 1989, Arch. Microbiol., 153, 50-59); Vitamin solution, 1.0 ml (Pfenning, N., Lippert, D., 1966, Arch. Mikrobiol. 55: 245-256); Yeast extract, 0.05 g; CaCl ₂ x 2 H ₂ O, 0.05 g. The pH was adjusted to 7.0 with 5 M KOH.] 10.0 g of agar were added and the solution was autoclaved at 121 ° C. for 20 min. The plastic was separated from the medium in ethanol pa and sterilized at 70 ° C for 30 min (2.0 g

Granules in 100 ml ethanol per liter medium). The two solutions were put together just before pouring the Agaφlatten

50 ° C,

70 ° C). This resulted in panels with a uniform turbidity. The microorganism strains according to the invention {Paenibaccillus lautus (DSM 11870), Bacillus pumilus (DMS 11871),

Aeromicrobium spec. (DSM 11872)) with a vaccine pea and the plates incubated at 27-37 ° C for several days to several weeks. The growth of the microorganisms was checked every 1-5 days. The degradation of the polymer is detected by the formation of a clear courtyard around a colony.

2. Thermophilic microorganisms (Thermobiψora biψora (DSM 11873), Bacillus ψec. RNA group V, Brevibacillus spec.) Were cultivated in a similar manner to that described under 1.) Incubation took place at 60 ° C. To avoid premature drying of the

Plates were incubated in an unsealed box containing a small bowl of water. After a few days the Degradation of the polymer visible through the formation of a clear courtyard around a colony.

3. For the cultivation of halophilic organisms (Bacillus pumilus (DSM 11871)), the medium described under 1. was supplemented by 30.0 g NaCl.

The microorganisms spread on this salt-rich medium were incubated at 27 ° C. After 4-8 weeks, a clearly visible courtyard formed around the colonies.

4. 1.0 ml of a bacterial suspension of a strain (Paenibaccillus lautus (DSM 11870), Bacillus pumilus (DSM 11871), Thermobiψora biψora (DSM 11873), Aeromicrobium spec. (DSM 11872)) were applied uniformly to an agar plate. After the plate had been completely covered by the organism and had become clear after polymer degradation, the agar was dissolved by agarase (Fluka, Neu-Ulm; activity: 6.4 U / mg). For this purpose, the microorganisms were first rinsed off the plates. The agar plate was transferred with a spatula into a 50 ml falcon tube. The mixture was heated to 100 ° C. without enzyme and the agar was dissolved. The mixture was then cooled to 48 ° C. and 250 μl of a 0.1% (wt / vol) solution of the agarase were added. The agar was incubated with the enzyme at 48 ° C. on the shaker. The incubation of the batches was stopped after complete lysis of the agar by heating the entire sample to 90 ° C. for 30 min. After the mixture had cooled, centrifugation was carried out at 12,000 φm and 4 ° C. for 15 minutes. The supernatant was sterile filtered. The content of adipic acid and

Determines aminocaproic acid. Adipic acid and aminocaproic acid are two of the monomers that make up the polymer under investigation. The results are summarized in Table 1. Table 1: Proven degradation products of the polyester amide after bacterial degradation

n.n. undetectable (content is below the detection limit)

Claims

claims

1. Process for the bacterial degradation of biodegradable polymers by at least one of the strains of the bacterial species Paenibaccillus lautus (DSM 11870, filing date November 24, 1997), Bacillus pumilus (DSM 11871,

Filing date 11/24/97, Aeromicrobium spec. (DSM 11872, filing date November 24, 1997), Thermobiψora biψora (DSM 11873, filing date November 24, 1997), Bacillus spec. RNA group V, Brevibacillus spec. as well as the esterases, lipases or oligo amidases to be obtained from them, the biodegradable polymers according to the invention being introduced into an aqueous nutrient solution and inoculated with a pure culture or a mixed culture of the bacterial species mentioned.

2. The method according to claim 1, wherein the polymer is present as a film, film, granules or as a coating, as a whole or comminuted.

3. The method according to claim 1, wherein as biodegradable polymers aliphatic or partially aromatic polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, which may also have urea groups, aliphatic-aromatic polyester carbonates and / or aliphatic or partially aromatic polyester amides are used.

4. The method according to claim 1 to 3, wherein the polymers used are:

Aliphatic or partially aromatic polyester

A) linear bifunctional alcohols and optionally cycloaliphatic bifunctional alcohols and optionally branched bifunctional alcohols

Alcohols and additionally optionally higher functional alcohols as well as from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally higher functional acids or B) from acid and alcohol functionalized building blocks or their derivatives

or a mixture or a copolymer of A and B,

wherein the aromatic acids make up no more than 50 wt .-% based on all acids, and the acids can also be used in the form of derivatives;

aliphatic or partially aromatic polyester urethanes, which may also have urea groups

C) an ester fraction of bifunctional alcohols and / or cycloaliphatic bifunctional or polycyclic aliphatic alcohols and / or optionally small amounts of branched bifunctional alcohols

Alcohols and, if appropriate, small amounts of higher-functional alcohols, as well as from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally small amounts of higher-functional acids or

D) from acid and alcohol functionalized building blocks, or their derivatives, or a mixture or a copolymer of C and D, and

E) from the reaction product C and / or D with aliphatic and / or cycloaliphatic bifunctional and additionally optionally higher-functional isocyanates, optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher-functional alcohols, and / or optionally additionally on loan linear and / or branched and / or cycloaliphatic bifunctional and / or higher functional dialkylamines or Amino alcohols and or optionally further modified amines or alcohols as free acid or salt,

Aliphatic-aromatic polyester carbonates

F) an ester fraction from linear bifunctional alcohols, and / or cycloaliphatic bifunctional alcohols, and / or optionally small amounts of branched bifunctional alcohols, and additionally optionally small amounts of higher functional alcohols, and from linear and / or cycloaliphatic bifunctional and additionally optionally small amounts of higher functional acids,

or

G) from acid- and alcohol-functionalized building blocks, or their derivatives,

or a mixture or a copolymer of F) and G) and

H) a carbonate portion, which is made from aromatic bifunctional phenols, and carbonate donors, wherein

the ester fraction F) and / or G) is at least 70% by weight, based on the sum of F), G) and H);

Aliphatic or partially aromatic polyester amides

I) an ester fraction from linear or aromatic alcohols, and / or cycloaliphatic bifunctional alcohols and / or optionally small amounts of branched bifunctional alcohols, and additionally optionally small amounts of higher functional alcohols, and from linear and / or cycloaliphatic bifunctional, and additionally optionally small amounts of higher functional acids, or

K) from acid- and alcohol-functionalized building blocks, or their derivatives,

or a mixture or a copolymer of I) and K) and

L) an amide content of linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional amines and additionally optionally small amounts of higher functional amines, and of linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional and additionally optionally small amounts Amounts of higher functional acids, or

or a mixture of L) and M) as the amide portion, the ester portion A) and / or B) being at least 30% by weight, based on the sum of I), K), L) and M),

where, as the alcohol component, monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights (weight average) of up to 4,000, preferably up to 1,000, can be used in part or in full instead of the diols.

5. The method according to claim 1 to 4, wherein as a bacterial species Paenibacillus lautus, Bacillus pumilus, Aeromicrobium spec, Thermobiψora biψora, Bacillus spec. RNA group V, Brevibacillus ψec. is used.

6. The method according to claim 1 to 5, wherein the temperature is between 15 and 70 ° C.

7. Microorganisms of the bacterial species Paenibacillus lautus (DSM 11870), Bacillus pumilus (DSM 11871), Thermobiψora biψora (DSM 11873) and

Aeromicrobium spec. (DSM 11872), filing date each November 24, 1997) and their mutants and variants which have the ability to degrade the polymers mentioned in the preceding claims.