249 results about "PHA biosynthesis" patented technology

Devices formed of or including biocompatible polyhydroxyalkanoates are provided with controlled degradation rates, preferably less than one year under physiological conditions. Preferred devices include sutures, suture fasteners, meniscus repair devices, rivets, tacks, staples, screws (including interference screws), bone plates and bone plating systems, surgical mesh, repair patches, slings, cardiovascular patches, orthopedic pins (including bone filling augmentation material), adhesion barriers, stents, guided tissue repair/regeneration devices, articular cartilage repair devices, nerve guides, tendon repair devices, atrial septal defect repair devices, pericardial patches, bulking and filling agents, vein valves, bone marrow scaffolds, meniscus regeneration devices, ligament and tendon grafts, ocular cell implants, spinal fusion cages, skin substitutes, dural substitutes, bone graft substitutes, bone dowels, wound dressings, and hemostats. The polyhydroxyalkanoates can contain additives, be formed of mixtures of monomers or include pendant groups or modifications in their backbones, or can be chemically modified, all to alter the degradation rates. The polyhydroxyalkanoate compositions also provide favorable mechanical properties, biocompatibility, and degradation times within desirable time frames under physiological conditions.

Polyhydroxyalkanoates (PHAs) from which pyrogen has been removed are provided for use in numerous biomedical applications. PHAs which have been chemically modified to enhance physical and/or chemical properties, for targeting or to modify biodegradability or clearance by the reticuloendothelial system (RES), are described. Methods for depyrogenating PHA polymers prepared by bacterial fermentation processes are also provided, wherein pyrogens are removed from the polymers without adversely impacting the polymers' inherent chemical structures and physical properties. PHAs with advantageous processing characteristics, including low melting points and/or solubility in non-toxic solvents, are also described. PHAs are provided which are suitable for use in in vivo applications such as in tissue coatings, stents, sutures, tubing, bone and other prostheses, bone or tissue cements, tissue regeneration devices, wound dressings, drug delivery, and for diagnostic and prophylactic uses. Properties which are selected for include degradability, elasticity, inclusion of functional groups or derivatized groups, which can in turn be used to attach targeting agents, and bioadhesion.

The invention discloses a PHBV with good performance and a copolymer of PHBV and PLA and the preparation technique method. The invention is characterized in that 1 per cent to 99 per cent of PHAs, 1 per cent to 99 per cent of PLA1 and other additives 0-40 per cent are put in a mixer for 1 to 30 minutes, and then put in an electricity hot blast drying oven a temperature ranging from 40 to 100 DEG C for 2 to 48 hours after being mixed equally. The dried compound is plastified in a double screw extruder, the highest temperature of the double screw extruder is between 90 and 180 DEG C according to the the different content of PHAs and the temperature of the mouth mold is between110 to 170 DEG C. The material extruded from a die head is cooled, stretched and grained to form the complete biodegradation aggregate. The resin consisting of PHBV and copolymer of PHBV and PLA is able to be used for producing the thin films, plates and sheet materials and injected mold to plastic materials. The compound has biological degradability and good machining performance. The target product of the compound has excellent mechanical properties and can be used for replacing the petroleum base plastic to be widely used for packing, agriculture, medical material, electron, chemical industry concerning products for daily use, etc.

The invention discloses slow-release fertilizer with the effect of soil remediation, which is prepared by polyhydroxyalkanoates which can be completely biodegraded, organic and inorganic nutrients and other substances, by slow-releasing the organic and inorganic nutrients, microorganism propagation and sustained and rapid growth of plants can be promoted, the bioactivity and water solubility of polycyclic aromatic hydrocarbons are quickened, and simultaneously, the defects of fertilizer loss and repeated fertilization can be avoided, thereby saving the cost and enhancing the soil remediation efficiency. The invention also discloses a soil pollution remediation method by utilizing the slow-release fertilizer, plants with the remediation effect are planted in the soil with the slow-release fertilizer, and efficient, environment-friendly and sustained remediation of the soil polluted by the polycyclic aromatic hydrocarbons (PAHs) can be realized by utilizing the microorganism-plant remediation technology.

Methods for the biosynthesis of polyhydroxyalkanoate homopolymers and copolymers are described. In a preferred embodiment, the polymers have a single mode molecular weight distribution, and more preferably have a distribution of between about 2 and about 4, and most preferably about 2.1 or 2.5.

Recombinant hosts for producing polyhydroxyalkanoates and methods of producing polyhydroxyalkanoates from renewable carbon substrates are provided. Certain recombinant hosts that produce 5 carbon chemicals such as 5-aminopentanoate (5AP), 5-hydroxyvalerate (5HV), glutarate, and 1,5 pentanediol (PDO) are also provided. One embodiment provides a recombinant host expressing a gene encoding a heterologous enzyme selected from the group consisting of a polyhydroxyalkanoate synthase and a 5-hydroxyvalerate-CoA (5HV-CoA) transferase, wherein the host produces a polymer containing 5-hydroxyvalerate. Preferably, the host expresses both a polyhydroxyalkanoate synthase and a 5HV-CoA transferase. The host can be prokaryotic or eukaryotic. A preferred prokaryotic host is E. coli. The polymers produced by the recombinant hosts can be homopolymers or copolymers of 5-hydroxyvalerate. A preferred copolymer is poly(3-hydroxybutyrate-co-5-hydroxyvalerate).

Provided are processes for the production and high efficiency processing of polyhydroxyalkanoates (PHA) from carbon sources comprising carbon-containing gases or materials.

The invention discloses a completely-biodegradable mulching film material which contains one kind or several kinds of compounds which are selected from a group consisting of polyhydroxy alkanoates, polylactic acid, poly(butylene adipate-co-terephthalate), poly(butylene-scuccinate/adipate) and poly(butylene-scuccinate). By adopting the completely biodegradable mulching film material, the yield of crops can be greatly improved, the mulching film material can be completely biodegradable without residues of a mulching film, and the yield of crops can be continuously increased.

The invention relates to a biodegradable multilayer material, which can be a thin film material or a sheet material. The biodegradable multilayer material at least comprises one of an adipic butanediol terephthalate copolymer (PBAT)/PBAT-chain extender-polypropylene carbonate (PBAT-Co-PPC)/PPC blend layer, a PBAT/PBAT-chain extender-polylactic acid (PBAT-Co-PLA)/PLA blend layer and a PBAT/PBAT-chain extender-polyhydroxyalkanoate (PBAT-Co-PHA)/PHA blend layer, and blend resins are respectively prepared through twin-screw reactive extrusion. The multilayer material is produced by using extrusion and coextrusion methods, has a function that the transmission rates of oxygen, carbon dioxide and water vapor can be adjusted, and can be applied to the packaging field and the agriculture field, and especially applied to food packaging, pharmaceutical packaging, and ground film mulching.

Polyhydroxyalkanoates comprising a monomer unit having the following chemical formula (2):

(where the reference characters R represents an arbitrarily selected substituent and x represents an integer of 0 to 8) is produced by culturing a microorganism in a culture medium containing a substituted fatty acid ester having the following chemical formula (1):

(where the reference characters R and R′ separately denote an optional substituent and x represents an integer of 0 to 8). The microorganism is capable of taking the substituted fatty acid ester into the cells and synthesizing the desired polyhydroxyalkanoate in the culture medium.

The invention discloses a biodegradable preservative film material which contains polyhydroxyalkanoate. The invention also discloses a preservative film prepared by the material, wherein the preservative film has a proper penetration rate and a good oxygen blocking function, so that some fruits and vegetables can retain proper moisture but not be contact with oxygen to prolong the preservative time; and in addition, the biodegradable preservative film material has a good preservative effect, and can be completely biodegraded after the preservative film is discarded after use, and pollution to the environment is not caused.

The invention discloses a full biodegradable N-poly-ester/poly butylene succinate blending alloy, which is characterized in that the blending alloy is prepared from N-poly-ester, poly butylene succinct, starch, filler and the other auxiliary agents. The blending alloy uses the heat resistance, good processing and forming property, higher crystallizing property, good tensile strength and impact toughness of the poly butylene succinate to improve the defects of poor heat resistance, serious processing and forming viscous, slow crystallization and lower mechanical strength of the N-poly-ester, and reduce the cost and widen the application range, the obtained blending alloy has good comprehensive performance, and can be applied in the fileds of blowing film, extruding sheets, injecting one-off environmental supplies and medical treatment.

The invention discloses modified polyurethane suspended filler which comprises, by weight, 10 parts to 80 parts of polyhydroxyalkanoate, 10 parts to 80 parts of activated carbon, 60 parts to 80 parts of polyurethane, 1 part to 10 parts of water-soluble polyurethane solutions, 0 part to 10 parts of bioactivator, 0 part to 1 part of inorganic metal salt, 0 part to 20 parts of organic high-molecular polymer and 0 part to 10 parts of inorganic flocculate. A preparation method of the modified polyurethane suspended filler includes the steps of taking the 10 parts to 80 parts of polyhydroxyalkanoate, the 10 parts to 80 parts of activated carbon, the 0 part to 10 parts of bioactivator, the 0 part to 1 part of inorganic metal salt, the 0 part to 20 parts of organic high-molecular polymer and the 0 part to 10 parts of inorganic flocculate, dissolving the mixture in the 1 part to 10 parts of water-soluble polyurethane solutions, soaking the 60 parts to 80 parts of polyurethane in the solution to obtain the loaded polyurethane suspended filler, and conducting secondary drying after primary drying is conducted to obtain the modified polyurethane suspended filler. The modified polyurethane suspended filler has the advantages of being high in porosity and large in specific area.

A method of biosynthesis of polyhydroxyalkanoates (PHA) is provided that includes providing a type II methanotrophic bacteria, and disposing the type II methanotrophic bacteria in an unbalanced growth condition, where the unbalanced growth condition includes a nutrient-deficient media and a hydroxyalkanoic acid, and where the nutrient-deficient media has an absence of an essential nutrient required for cell replication of the type II methanotrophic bacteria.

The invention relates to a biological degradation foamed plastic which comprises the following components and contents: polylactic acid resin: 100 portions; polylactic acid plasticizer: 10 to 20 portions; polyhydroxy alkanoates multipolymer: 10 to 50 portions; corn starch: 20 to 60 portions; foaming agent: 8 to 17 portions; blowing promoter: 2 to 4 portions; lubricant: 0.8 to 1.2 portions; antiager: 0.45 to 0.70 portion, and the amount is calculated by weight. The biological degradation foamed plastic of the invention also provides a manufacturing method for manufacturing the biological degradation foamed plastic. The biological degradation foamed plastic is characterized by low density, high specific strength, good shock absorption performance and complete biological degradation, can be applied not only in the shock absorption packages of industrial products, such as domestic appliances, electron, instruments, industrial fittings and glass/ceramic etc., but also in a field that needs heat preservation and thermal insulation, thus the biological degradation foamed plastic of the invention is a new environmental-friendly packaging material.

The invention discloses a device and a method capable of realizing simultaneous phosphorus and nitrogen removal from sewage in a low C/N ratio by coupling enhanced biological phosphorus removal with simultaneous shortcut nitrification and denitrification and belongs to the field of biological sewage treatment. After entering an SBR coupling enhanced biological phosphorus removal with simultaneous shortcut nitrification and denitrification, sewage is first subjected to anaerobic stirring, and GAOs (glycogen-accumulating organisms) and PAOs (phosphorus-accumulating organisms) absorb organic carbon sources from the sewage and synthesize an internal carbon source PHA (polyhydroxyalkanoates) to be stored in bodies; then the sewage is subjected to low-oxygen aeration stirring, AOB (ammonia oxidizing bacteria) play a role in shortcut nitrification to convert ammonia nitrogen into nitrite nitrogen, and the PAOs decompose the PHA for aerobic phosphorus accumulation so as to create a hypoxic microenvironment beneficial to that the GAOs and the PAOs use the nitrite nitrogen produced during shortcut nitrification for endogenous denitrification and denitrifying phosphorus removal respectively. The method coupling enhanced biological phosphorus removal with simultaneous shortcut nitrification and endogenous denitrification is capable of realizing simultaneous phosphorus and nitrogen removal from the sewage in the low C/N ratio without addition of a carbon source, so that oxygen consumption and energy consumption are reduced and urban sewage treatment costs are saved.

Embodiments of the invention relate generally to processes for the production and processing of polyhydroxyalkanoates (PHA) from carbon sources. In several embodiments, PHAs are produced at high efficiencies from carbon-containing gases through the utilization of a regenerative polymerization system.

The invention relates to a novel degradable medical magnesium alloy composite material. The medical magnesium alloy composite material provided by the invention has the characteristics of high strength, good temperature memory and controllable degradation velocity and can be used in the field of orthopedic implantation. The composite material is characterized in that the composite material contains Mg-Al-Zn magnesium alloys, wherein the content of Al is 0.5-3.5wt% and the content of Zn is 0.5-1.8wt%; besides, the magnesium alloy material can contain a few impurities including Fe, Mn, Cu and Ni, wherein the total of the impurities is not greater than 0.3wt%; and a medical biology degradable material exists on the surface layer of the composite material and can be a pure carbon dioxide copolymer, pure polyhydroxyalkanoate or a blend of the carbon dioxide copolymer and polyhydroxyalkanoate, which has to be medically purified before use.