Chemistry: molecular biology and microbiology – Micro-organism – tissue cell culture or enzyme using process... – Preparing oxygen-containing organic compound
Reexamination Certificate
2003-02-25
2003-11-11
Acquah, Samuel A. (Department: 1711)
Chemistry: molecular biology and microbiology
Micro-organism, tissue cell culture or enzyme using process...
Preparing oxygen-containing organic compound
C528S361000, C528S363000, C528S364000, C528S365000, C528S373000, C528S378000, C528S380000, C528S422000, C525S450000, C525S535000, C525S540000, C524S732000, C524S734000, C524S770000, C524S773000, C435S135000, C435S253300, C435S255100, C435S874000, C435S877000
Reexamination Certificate
active
06645743
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polyhydroxyalkanoate copolymer that contains a novel unit, and a method of manufacturing the same utilizing microorganisms.
2. Related Background Art
Heretofore, it has been reported that many microorganisms produce poly-3-hydroxybutyrate (PHB) or other polyhydroxyalkanoate (PHA) and accumulate the products in their microbial bodies (“Biodegradable Plastics Handbook”, Biodegradable Plastics Society, Ed., pp. 178-197, (1995) published by NTS Co., Ltd., JAPAN). Polymers such as PHA produced by microorganisms can be used for manufacturing various kinds of products by melting process and so on just as in the case of the conventional plastics. Furthermore, polymers such as PHA produced by microorganisms are biodegradable, so that there is an advantage in that they can be completely decomposed by microorganisms in nature. Therefore, PHA or the like originated from microorganisms has no tendency to remain as it is in the natural environment when it is disposed. It means that it will not become a factor of causing environmental pollution while many of the conventional synthetic polymer compounds become factors thereof. Furthermore, the microorganism-produced PHA has an excellent biocompatibility in general, so that it has been expected that it would be used in many applications such as a medical soft structural member.
It has been also known that the microorganism-produced PHA would have various compositions and configurations depending on the species of microorganisms used in the production, the formulations of culture media, culture conditions, and so on. Up to now, from the viewpoint of mainly improving the physical properties of PHA, studies on control of the composition and configuration of the microorganism-produced PHA have been carried out.
As one of the studies which have been made aiming at controlling the composition or configuration of the microorganism-produced PHA, in recent years, the attempts to produce PHA having an aromatic ring in its unit from a microorganism have been extensively conducted.
In each of “Makromol. Chem.”, 191, 1957-1965 (1990) and “Macromolecules”, 24, 5256-5260 (1991), it is reported that Pseudomonas oleovorans uses 5-phenyl-valeric acid as a substrate to produce PHA that contains 3-hydroxy-5-phenyl-valerate as a unit thereof. In “Macromolecules”, 29, 1762-1766 (1996), it is reported that Pseudomonas oleovorans uses 5-(p-tolyl)-valeric acid as a substrate and produces PHA that contains 3-hydroxy-5-(p-tolyl)-valerate as a unit thereof. In “Macromolecules”, 32, 2889-2895 (1999), furthermore, it is reported that Pseudomonas oleovorans uses 5-(2,4-dinitrophenyl)-valeric acid as a substrate to produce PHA that contains two different units: 3-hyroxy-5-(2,4-dinitrophenyl)-valerate and 3-hydroxy-5-(p-nitrophenyl)-valerate. Furthermore, in “Macromol. Chem. Phys.”, 195, 1665-1672 (1994), it is reported that Pseudomonas oleovorans uses 11-phenoxy-undecanoic acid as a substrate to produce a PHA copolymer that contains two different units: 3-hydroxy-5-phenoxy-valerate and 3-hydroxy-9-phenoxy-nonanoate.
Furthermore, JP 2989175 B discloses the invention relating to: a homopolymer that contains a unit of 3-hydroxy-5-(monofluorophenoxy)-pentanoate (3H5(MFP)P) or a unit of 3-hydroxy-5-(difluorophenoxy)-pentanoate (3H5(DFP)P); a copolymer that contains at least the 3H5(MFP)P unit or the 3H5(DFP)P unit; Pseudomonas putida having the abilities of producing these polymers; and a method of manufacturing the above polymers using genus Pseudomonas. In addition, Japanese Patent Publication No. 2989175 describes as an effect of the invention that a polymer that contains a unit obtained by the substitution of phenoxy groups having one or two substituted fluorine atoms on the end of a side chain can be synthesized by utilizing long-chain fatty acids having substituents. In addition, it is also described that such a polymer keeps a good processability in addition to its high melting point, and further described that such a polymer can be provided with stereoregularity and water repellency.
In addition to the study of PHA that contains in its structural unit a fluorine-substituted aromatic ring group with a fluorine substituent on its aromatic ring, the study of PHA that contains in its structural unit a substituted aromatic ring group having a substituted cyano or nitro group on its aromatic ring is reported.
Furthermore, “Can. J. Microbiol.”, 41, 32-43 (1995) and “Polymer International”, 39, 205-213 (1996) report the production of PHA that contains a monomer unit of 3-hydroxy-6-(p-cyanophenoxy)-hexanoate or 3-hydroxy-6-(p-nitrophenoxy)-hexanoate from Pseudomonas oleovorans ATCC29347 strain and Pseudomonas putida KT2442 strain using octanoic acid and 6-(p-cyanophenoxy)-hexanoic acid or 6-(p-nitrophenoxy)-hexanoic acid as substrates, respectively.
These PHAs, which contain units having aromatic rings with substituents thereon, keep their own polymer properties derived from the aromatic rings, such as high glass-transition temperatures and good processabilities. In addition, these PHAs are provided with additional functions derived from the substituents on the aromatic rings. Therefore, the PHAs become multi-functional PHAs.
On the other hand, for preparing multi-functional PHA by introducing any functional group into the side chain of the produced polymer by a chemical conversion using the vinyl group, studies have been also extensively conducted on the basis of PHA that contains a structural unit having a vinyl group on its side chain.
In “Polymer”, 41, 1703-1709 (2000), it is reported that polyester having a hydroxyl group on its side chain is produced by producing polyester having a vinyl group on its side chain using Pseudomonas oleovorans and oxidizing the vinyl group in the molecule of the polyester.
Similarly, in “Macromolecules”, 31, 1480-1486 (1998), reported is the production of polyester having an epoxy group on its side chain by producing polyester having a vinyl group on its side chain using Pseudomonas oleovorans and epoxidizing the vinyl group.
In “Polymer”, 40, 3787-3793 (1999), furthermore, polymer having an epoxy group on its side chain, which is obtained by the same method as described above, is subjected to a crosslinking reaction by heating it together with hexamethylene diamine. In this document, such a reaction and the results of analyzing the reaction product are reported.
Furthermore, in “Polymer”, 35, 2090-2097 (1994), reported is the study of improving the physical properties of polyester, in which a vinyl group on the side chain of the polyester is used to permit a crosslinking reaction in the molecule of polyester.
SUMMARY OF THE INVENTION
As is evident from these conventional studies listed above, as the vinyl group is an unsaturated hydrocarbon group, the vinyl group shows a high reactivity in an addition reaction or the like and is capable of introducing various kinds of functional groups and conducting chemical conversion. Furthermore, the vinyl group on the side chain of the polymer would be a stepping stone to the crosslinking reaction of the polymer, i.e., a crosslinking point. Therefore, the vinyl group provided in the structural unit of PHA can be very useful for considering the range of applications of polymer as a functional material.
In each of these conventionally reported polyhydroxyalkanoates that contain structural units having vinyl groups on their side chains, the structural unit has a structure in which a vinyl group is substituted at the end of an alkyl side chain directly bonded to a polyhydroxyalkanoate main chain skeleton, for example, a 3-hydroxy-&ohgr;-vinyl-alkanoate unit. However, as with an alkyl chain on which a vinyl group is substituted at the end thereof, the thermal characteristics of polyhydroxyalkanoate having a side chain with a straight carbon chain skeleton are not always preferable (e.g., glass transition temperature and melting point are not generally so high) for melting process. For providing films, processed products, a
Fukui Tatsuki
Honma Tsutomu
Imamura Takeshi
Kenmoku Takashi
Sugawa Etsuko
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