Abstract: The object of this invention is to provide a method for purifying PHA separated from PHA-containing microbial cells in high purity without incurring any serious decrease in molecular weight. The present invention provides a method for purifying a 3-hydroxyalkanoic acid copolymer produced by a microorganism, which comprises treating an aqueous suspension containing the 3-hydroxyalkanoic acid copolymer separated from a microorganism with a hydrogen peroxide while controlling the pH of said aqueous suspension by adding an alkali either continuously or intermittently.

Abstract: The present invention provides a method to efficiently degrade nucleic acids, which result in a viscosity increase of the solution thereof on the occasion of decomposition or solubilization of microbial cells, in an easy and simple manner in the step of recovering various useful substance produced by a microorganism, and a use thereof. The product recovery method of the present invention make the product recovery from within microbial cells with ease under relatively mild conditions, because, by bringing living microbial cells into contact with a little amount of hypochlorous acid or a salt thereof, autodigestion of nucleic acids is induced and following decomposition of microbial cells or viscosity increase of the solution thereof after dissolution is inhibited. The method of the present invention is particularly preferred in recovering polyhydroxyalkanoates, which are biodegradable polymers, from microbial cells.

Abstract: This invention relates to a method of producing polyesters resulting from homopolymerization or copolymerization of a 3-hydroxyalkanoic acid(s) and having biodegradability and good physical properties using yeasts as hosts. By constructing at least one enzyme gene involved in polyester synthesis by adding a DNA coding a peroxisome-targeting signal, introducing an enzyme gene expression cassette containing that gene into yeast, and cultivating the thus-obtained transformant, it becomes possible to cause accumulation of a polyester resulting from homopolymerization or copolymerization of a 3-hydroxyalkanoic acid(s) in yeast cells and recover the polyester from the culture.

Abstract: The present invention has an object to provide a method for separating and purifying a PHA without causing a serious decrease of the molecular weight to obtain a highly pure PHA in a high yield, which comprises efficiently removing cell components other than PHA particles from a cultured PHA-containing microbial cell. Another object of the present invention is to provide a method for obtaining an agglomerate of PHA particles. The method for recovering a PHA according to the present invention is a method which comprises efficiently disrupting a cell to recover the PHA by carrying out a physical disruption treatment and an alkali addition at low temperature for an aqueous suspension of the PHA-containing microbial cell, and then treating the PHA with an enzyme and/or a surfactant. Moreover, the particle diameter of the PHA may be enlarged by suspending the PHA in a hydrophilic solvent and/or water, and stirring at a temperature equal to or below the boiling point of said suspension, to agglomerate said PHA.

Abstract: The present invention has for its object to provide a method for agglomerating particles of a poly-3-hydroxyalkanoic acid and enlarging its particle size. The present invention provides a method for agglomerating a poly-3-hydroxyalkanoic acid which comprises suspending particles of the poly-3-hydroxyalkanoic acid in a hydrophilic solvent or a mixture comprising water and a hydrophilic solvent, and stirring the obtained suspension at a temperature not more than the boiling point of said suspension.

Abstract: The present invention provides a production method of a copolymeric polyester which comprises culturing an ACT1 gene promoter shown under SEQ ID NO: 9, a GAP3 gene promoter shown under SEQ ID NO: 10; a PMA1 gene promoter shown under SEQ ID NO: 11, and, a TEF1 gene promoter shown under SEQ ID NO: 12; a plasmid which contains the gene expression unit comprising said promoter; a transformed cell as resulting from transformation of the said plasmid; and said transformed cell.

Abstract: The invention aims at providing a method of producing a poly-3-hydroxyalkanoic acid, which comprises carrying out a physical disruption treatment of a suspension of poly-3-hydroxyalkanoic acid-containing microbial cells with adding an alkali thereto either continuously or intermittently and, thereafter, separating the poly-3-hydroxyalkanoic acid.

Abstract: The present invention provides a method for easily obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method. A method for producing a polyhydroxyalkanoate crystal comprises mixing a solution of a polyhydroxyalkanoate in a good solvent with a poor solvent at 50 to 130° C. to precipitate a polyhydroxyalkanoate.

Abstract: The present invention provides a method for conveniently obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method. A method for producing a polyhydroxyalkanoate crystal comprises precipitating a polyhydroxyalkanoate crystal using a monohydric alcohol having 4 to 10 carbon atoms as a extraction solvent, keeping a polyhydroxyalkanoate solution containing 0.1 to 10% by weight of water relative to the total amount of the solution warm at 70° C. or higher, and cooling the solution to below 70° C.

Abstract: The present invention relates to a gene coding for a copolyester-synthesizing enzyme, a microorganism which utilizes the gene for the fermentative synthesis of a polyester, and a method of producing a polyester with the aid of the microorganism. More particularly, the present invention relates to a gene which functions in a host organism and, by an enzyme, synthesizes a plastic-like polymer degradable under the action of microorganisms in the natural environment (the soil, river or sea). The present invention also, more particularly, relates to a transformant derived from the host organism by transformation with the gene and having an improved ability to fermentatively synthesize a plastic-like polymer, and a method of producing a copolyester with the aid of the transformant.

Abstract: The invention provides a yeast in which a specific gene alone has been disrupted and to which auxotrophy is impared to construct a system for producing an industrially useful substance through gene recombination by utilizing characteristics of a yeast. In the practice of the invention, a yeast strain in which ADE1 gene has been disrupted is constructed by homologous recombination with a chromosomal DNA by using an ADE1 gene fragment encoding phosphoribosylaminoimidazole succinocarboxamide synthase (EC6.3.2.6) of Candida maltosa. In the practice of the invention, then, this disrupted strain is transformed by a gene expression cassette containing a biodegradable polyester synthase gene and the obtained transformant is cultured to thereby produce biodegradable polyester.

Abstract: The object of this invention is to provide a method for purifying PHA separated from PHA-containing microbial cells in high purity without incurring any serious decrease in molecular weight. The present invention provides a method for purifying a 3-hydroxyalkanoic acid copolymer produced by a microorganism, which comprises treating an aqueous suspension containing the 3-hydroxyalkanoic acid copolymer separated from a microorganism with a hydrogen peroxide while controlling the pH of said aqueous suspension by adding an alkali either continuously or intermittently.

Abstract: The present invention has its object to provide a method of producing PHA by extracting, separating, and purifying PHA from biomass containing PHA having an weight average molecular weight of more than 2,000,000, by which smooth stirring can be carried out during extraction and filterability of a residue becomes good to thereby efficiently produce PHA with good operability. In the present invention, PHA is extracted, separated, and purified from biomass by a method of producing polyhydroxyalkanoate by extracting and isolating polyhydroxyalkanoate by using an aprotic organic solvent from biomass containing polyhydroxyalkanoate having a weight average molecular weight of more than 2,000,000, which comprises decreasing the weight average molecular weight of the polyhydroxyalkanoate through any one of the following treatments: (a) the biomass is heated at 40 to 500° C. before addition of the aprotic organic solvent; (b) the biomass is heated at 40 to 500° C.

Abstract: The invention aims at providing a method of producing a poly-3-hydroxyalkanoic acid, which comprises carrying out a physical disruption treatment of a suspension of poly-3-hydroxyalkanoic acid-containing microbial cells with adding an alkali thereto either continuously or intermittently and, thereafter, separating the poly-3-hydroxyalkanoic acid.

Abstract: The present invention has an object to provide a method for separating and purifying a PHA without causing a serious decrease of the molecular weight to obtain a highly pure PHA in a high yield, which comprises efficiently removing cell components other than PHA particles from a cultured PHA-containing microbial cell. Another object of the present invention is to provide a method for obtaining an agglomerate of PHA particles. The method for recovering a PHA according to the present invention is a method which comprises efficiently disrupting a cell to recover the PHA by carrying out a physical disruption treatment and an alkali addition at low temperature for an aqueous suspension of the PHA-containing microbial cell, and then treating the PHA with an enzyme and/or a surfactant. Moreover, the particle diameter of the PHA may be enlarged by suspending the PHA in a hydrophilic solvent and/or water, and stirring at a temperature equal to or below the boiling point of said suspension, to agglomerate said PHA.

Abstract: The present invention provides a method for obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method without causing a significant molecular weight decrease. The present invention relates to a method for producing a polyhydroxyalkanoate which comprises extracting a polyhydroxyalkanoate from a polyhydroxyalkanoate-containing biomass having the water content of 5% by weight or less using an extraction solvent, crystallizing, and recovering the resultant.

Abstract: The present invention provides a method for conveniently obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method. A method for producing a polyhydroxyalkanoate crystal comprises precipitating a polyhydroxyalkanoate crystal using a monohydric alcohol having 4 to 10 carbon atoms as a extraction solvent, keeping a polyhydroxyalkanoate solution containing 0.1 to 10% by weight of water relative to the total amount of the solution warm at 70° C. or higher, and cooling the solution to below 70° C.

Abstract: The present invention provides a method for easily obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method. A method for producing a polyhydroxyalkanoate crystal which comprises mixing a solution of a polyhydroxyalkanoate in a good solvent with a poor solvent at 50 to 130° C. to precipitate a polyhydroxyalkanoate.

Abstract: The present invention provides a method to efficiently degrade nucleic acids, which result in a viscosity increase of the solution thereof on the occasion of decomposition or solubilization of microbial cells, in an easy and simple manner in the step of recovering various useful substance produced by a microorganism, and a use thereof. The product recovery method of the present invention make the product recovery from within microbial cells with ease under relatively mild conditions, because, by bringing living microbial cells into contact with a little amount of hypochlorous acid or a salt thereof, autodigestion of nucleic acids is induced and following decomposition of microbial cells or viscosity increase of the solution thereof after dissolution is inhibited. The method of the present invention is particularly preferred in recovering polyhydroxyalkanoates, which are biodegradable polymers, from microbial cells.

Abstract: The present invention provides a method for obtaining a novel antigen to which antibodies associated with rheumatoid arthritis (RA) reacts specifically and detecting RA patients by using the antigen, as well as a composition and a kit for the same. cDNA libraries were made from synovial cells, and a screening for the antigen was conducted by using IgG in synovial fluid from RA patients. Thus, a clone A polypeptide, which is a novel polypeptide as a RA antigen, and follistatin related protein (FRP), which is known as a polypeptide but novel as a RA antigen, were isolated. An antibody to these polypeptide antigens or their derivatives was detected. These polypeptides could provide a marker for prediction or diagnosis of RA.