Abstract: 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.

Abstract: The N-terminal amino acid sequence of the polyhydroxyalkanoic acid (PHA) granule-associated M.sub.r 15,500 protein of Rhodococcus ruber, which is referred to as the GA14-protein, was analysed. The sequence revealed that the corresponding structural gene is represented by the open reading frame 3 encoding a protein with a calculated M.sub.r 14,175 which was recently localized downstream of the PHA synthase gene (Pieper, U., and A. Steinbuchel, 1992. FEMS Microbiol. Lett. 96: 73-80). A recombinant strain of Escherichia coli XL1-Blue carrying the hybrid plasmid (pSKXA10*) with ORF3 overexpressed the GA14-protein. The GA14-protein was subsequently purified in a three-step procedure including chromatography on DEAE-Sephacel, Phenyl-Sepharose CL-4B and Superose 12. Determination of the molecular weight by gel filtration as well as electron microscopic studies make a tetrameric structure of the recombinant, native GA14-protein most likely.

Abstract: A full length cDNA of rape seed .beta.-ketoreductase pJRS 10.1 having the Sequence ID-1.

Abstract: A polymer composition comprises an aliphatic polyester and at least one compound of the general formula (I): R.sup.1.sub.a (A)R.sup.2.sub.b, where A is a polyfunctional hydrocarbon group; R1 is an electron-donating group such as hydroxy, amino, thiol, or a derivative thereof; R2 is an electron-withdrawing group such as carboxylic acid, carboxylic amide and quaternary onium; and a and b are at least 1.

Abstract: Hydroxyterminated PHA is produced by cultivating a PHA-producing microorganism in the presence of an aliphatic diol or an aliphatic polyol. High molecular weight hydroxy-terminated PHA is obtainable by the disclosed process, and is useful in the production of graft, block and random polymers and copolymers with other monomers, oligomers and polymers containing appropriate functionality and end group compatibility.

Abstract: A method for purifying and recovering biologically active somatotropin monomers from refold solution following the solubilization and naturation of refractile bodies of host cells produced by recombinant DNA methodology. The purification process is based on the discovery that somatotropin monomers and somatotropin oligomers having overlapping isoelectric points may nevertheless be separated by selective precipitation over a narrow pH range. Host cell residues including proteins, pyrogens and other impurities present in the refold solution are effectively removed in the process. The purified somatotropin monomers recovered from solution after removing precipitated solids are suitable for parenteral application to target animals without further purification.

Abstract: A hydroxycarboxylic acid copolyester of R-stereospecific configuration contains a majority of first repeating units capable of forming a highly crystalline high-melting homopolyester and a minority of second repeating units capable when randomly copolycondensed with said first repeating units of lowering the melting point of said homopolyester and is characterised by one or more of: higher crystalline melting point, shorter crystallising time, higher notched impact strength at age 1 month, as compared with corresponding random polyester, and said majority repeating units in the polyester chain being present in blocks longer than correspond to their over-all molar proportionality. The copolyester may be made by fermentation, controlling the distribution of repeating units by reference to the pattern of feeding substrates corresponding to the respective repeating units.

Abstract: A chiral (R) stereospecific polyhydroxyalkanoate (PHA) in aqueous latex form having virgin disperse phase particles of very low or undetectable crystallinity is useful in making a water-sensitive structure water-resistant. It may be used as a mixture with a latex of a synthetic polymer. Processes for making the PHA latex are disclosed.

Abstract: Genes and methods for optimizing levels of substrates employed in the biosynthesis of copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) in plants and bacteria via manipulation of normal metabolic pathways using recombinant DNA techniques are provided. This is achieved through the use of a variety of wild-type and/or deregulated enzymes involved in the biosynthesis of aspartate family amino acids, and wild-type or deregulated forms of enzymes, such as threonine deaminase, involved in the conversion of threonine to P(3HB-co-3HV) copolymer endproduct. By these methods, enhanced levels of threonine, .alpha.-ketobutyrate, propionate, propionyl-CoA, .beta.-ketovaleryl-CoA, and .beta.-hydroxyvaleryl-CoA are produced. Also provided are methods for the biological production of P(3HB-co-3HV) copolymers in plants and bacteria utilizing propionyl-CoA produced through a variety of engineered metabolic pathways. Introduction into plants and bacteria of an appropriate .beta.-ketothiolase, .beta.

Abstract: Methods and materials for the production of transgenic soybeans are disclosed. Preparation of explants from specific regions of soybean seedlings resulted in improved transformation efficiencies. Incubation of soybean seedlings between about 0.degree. C. and about 10.degree. C. prior to preparing explants was found to be further beneficial to the preparation of transgenic soybeans.

Abstract: A process of recovering PHA from a suspension which comprises particles of PHA in a liquid which comprises maintaining the suspension at a temperature at which the PHA melts and substantial coalescence of PHA particles occurs thereby at least partly forming a layer of molten PHA and separating the layer of PHA optionally after it cooling to form a solid.

Abstract: Genes and methods for optimizing levels of substrates employed in the biosynthesis of copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) in plants and bacteria via manipulation of normal metabolic pathways using recombinant DNA techniques are provided. This is achieved through the use of a variety of wild-type and/or deregulated enzymes involved in the biosynthesis of aspartate family amino acids, and wild-type or deregulated forms of enzymes, such as threonine deaminase, involved in the conversion of threonine to P(3HB-co-3HV) copolymer end product. By these methods, enhanced levels of threonine, .alpha.-ketobutyrate, propionate, propionyl-CoA, .beta.-ketovaleryl-CoA, and .beta.-hydroxyvaleryl-CoA are produced. Also provided are methods for the biological production of P(3HB-co-3HV) copolymers in plants and bacteria utilizing propionyl-CoA produced through a variety of engineered metabolic pathways. Introduction into plants and bacteria of an appropriate .beta.-ketothiolase, .beta.

Abstract: A hydroxyalkanoic acid (PHA)is recovered from matter derived from living organisms by dissolving the PHA in a solvent which is a lower ketone, dialkyl ether or a lower alcohol or a monocarboxylic acid ester thereof, separating the solution from such matter and recovering PHA from the solution.

Abstract: A process of making a polyhydroxyalkanoate PHA latex comprises making a liquid-form solution of such PHA in a water soluble liquid and contacting that solution with water under shear. Suitably the solution is prepared at a temperature between the boiling point of water and 10.degree. C. below the melting point of the PHA as measured by DSC for example by melt separating PHA from a microbiological suspension thereof, dissolving it in the water soluble liquid, and then contacting the solution at over 100.degree. C. with water at 50.degree.-95.degree. C. The water-soluble liquid may be for example 1,2-propandiol or a liquid more volatile than water such as ethanol, propanol or tertiary butanol. A surfactant may be present or added after contacting, for example one providing steric stabilisation such as an acrylic graft copolymer emulsifier.

Abstract: Process for improving mechanical properties of an aged polyester composition consisting essentially of copolymer of hydroxybutyrate units and hydroxyvalerate units which comprises heating the polyester at a temperature whereby (i) the polyester is restored to its original non-aged properties, and (ii) subsequent ageing of the polyester is retarded as indicated by substantial improvement of at least one measurement indicative of ageing compared to non heat treated polyester of the same age. The invention includes the polyester composition and shaped articles which have been subjected to the process and in which ageing is retarded.

Abstract: A process for producing poly-3-hydroxyalkanoate (PHA) by culturing Alcaligenes on a low water-solubility aliphatic carboxylic acid and, or hydrolysable derivative of low solubility in pure water, by fermenting the organism in a growth step on a nutrient medium containing inter alia phosphorus in a quantity corresponding to the intended quantity of bacterial cells to be grown until cell growth stops or slows substantially, then in a PHA accumulation stage fermenting the grown cells by feeding said low-solubility carbon source while monitoring pH and adjusting it by addition of ammonia and/or alkaline alkali metal compound until a design quantity of PHA has been produced, and recovering PHA from the product. Further phosphorus may be fed to the accumulation stage at a rate sufficient to permit some bacterial growth but insufficient to permit growth to the exclusion of PHA accumulation.

Abstract: Isolated DNA fragments encoding a Rhodospirillum rubrum (ATCC 25903) polyhydroxyalkanoate (PHA) synthase, or biologically functional equivalents thereof, are provided. Also provided is the deduced amino acid sequence of the R. rubrum PHA synthase. These molecules are useful in the production of PHAs in bacteria and plants.

Abstract: Method of retarding age embrittlement of polyester comprising heat treating the polyester after preparation by cooling below 90.degree. C. and then heating at 90.degree. C. to 160.degree. C. within 24 hours of preparation, and a polyester composition in which ageing is substantially retarded compared to the non-heat treated polyester. The invention encompasses the polyester composition which has been subjected to the method.

Abstract: There is provided a method for purifying a refold somatotropin monomer from a mixture of somatotropin monomers and somatotropin oligomers in an aqueous solution having a urea concentration of greater than 3 molar by the addition of an acid to reduce the pH of the solution to below about 7.7 to selectively precipitate the oligomers in the most part.

Abstract: A genomic fragment harboring the gene phaG was cloned by phenotypic complementation of Pseudomonas putida KT2440 mutants, defective in the polyhydroxyalkanoic acid (PHA) synthesis via de novo fatty acid biosynthesis but not affected in PHA biosynthesis via fatty acid .beta.-oxidation. The 885-bp phaG gene encodes a protein of 295 amino acids with a molecular weight of 33,876 Da. The transcriptional induction of phaG could be observed under conditions of PHA synthesis via de novo fatty acid biosynthesis whereas no induction was detected under conditions which favor PHA synthesis via fatty acid degradation by .beta.-oxidation. The phaG gene is useful for the production of PHAs in bacteria and plants.