Abstract: The present invention provides a process for the preparation of D-asparagine derivatives of formula I wherein R1 is an amino protecting group and R2 is an alkyl, a substituted alkyl or a group of formula A R3(OCH2CH2)n—  A wherein R3 is hydrogen or an lower alkyl group and n is 1, 2 or 3, which process comprises reacting a compound of formula II wherein R1 and R2 are as defined above, with a protease in an aqueous solution at a pH of 6.0-7.5 and an organic solvent, and subsequently extracting the enantiomeric pure product of formula I. Compounds of formula I can be used as intermediates in the production of antibacterial substances.

Abstract: This invention relates to the isolation of a novel putative efflux gene from Pseudomonas mendocina. The putative efflux gene is useful for probing an organism's efflux system to gain an understanding of the mechanisms of solvent tolerance. The invention further provides a Pseudomonas mendocina strain deficient in this gene. This strain is unable to grow in the presence of chloramphenicol and, compared to the wildtype strain, grows slowly in the presence of high concentrations of PHBA.

Abstract: The invention provides a process for the fermentative preparation of L-amino acids using coryneform bacteria, in which the subunit carrying the biotin-carboxyl carrier protein domain and the biotin-carboxylase domain of the nucleotide sequence encoding the enzyme acetyl-CoA carboxylase (accBC gene) is amplified, in particular is overexpressed.

Abstract: The invention provides a process for the production of aspartic acid poly-condensate from a carbohydrate comprising the steps of: fermenting a carbohydrate-containing medium by means of a fumaric acid-producing microorganism, whereby a fumarate-containing fermentation liquor is formed; forming a purified ammonium fumarate solution from the fumarate-containing fermentation liquor; enzymatically converting the purified ammonium fumarate into purified ammonium aspartate; heating an aqueous solution of an aspartate salt derived from the purified ammonium aspartate whereby water is removed, an aspartic acid condensate is formed and a second product is formed, which second product is basic and contains the cation of the aspartate salt; and removing and using the basic second product as a reagent in another step of the process.

Abstract: The present invention provides a process for the preparation of D-asparagine derivatives of formula I 1

Abstract: A succinimide polymer is produced by thermally polymerizing an ammonium salt of aspartic acid in the presence of an acid catalyst such as a boric acid catalyst. Another amino acid may be added for copolymerizing with the ammonium salt of aspartic acid. Ammonia liberated during the production of a succinimide polymer can be collected in a fumaric acid suspension, an acidic fumaric acid solution, a maleic acid solution or an acidic maleic acid solution, and the resultant liquid reacted with an enzyme which may be immobilized to produce L-aspartic acid. An aspartic acid polymer is produced by hydrolyzing the succinimide polymer with a basic substance.

Abstract: A process for production of L-aspartic acid comprising (1) contacting (A) an enzyme-containing material having maleate isomerase activity and aspartase activity, or (B) an enzyme-containing material having maleate isomerase activity and an enzyme-containing material having aspartase activity, with an aqueous substrate solution containing maleic acid and ammonia, and/or mono or di-ammonium maleate, to form L-ammonium aspartate, in a reaction solution, (2) adding the reaction solution to an aqueous solution of maleic acid or maleic anhydride at a controlled rate to crystallize L-aspartic acid in a mother liquor, and (3) recovering the L-aspartic acid from the mother liquor, and (4) optionally recycling said mother liquor as a substrate solution for further reaction with said enzyme containing material of Step 1 and (5) optionally adding alkali such as ammonia to said mother liquor before, during, or after recycle.

Abstract: An improved process for preparing L-aspartic acid by enzyme-catalyzed reaction of fumaric acid with ammonia, in which process L-aspartic acid is precipitated out by nitric acid and the resultant mother liquor is subjected to a nanofiltration.

Abstract: The use of strains of the genus Microbacterium for the production of organic acids or amino acids by the enzymatic conversion of a fumaric acid to the organic acid or amino acid desired, as well as methods for such use and the conversion solution produced by such use and the methods of the present invention are disclosed. The uses and the methods of the present invention provide the L-isomer form of the desired organic acid or amino acid produced thereby in the absence of the D-isomer form of the desired organic acid or amino acid. Also disclosed are reactants solutions which include the strain of the genus Microbacterium and the L-isomer form of either the organic acid or the amino acid.

Abstract: This invention relates to a method for producing L-aspartic acid, comprising the steps of: immobilizing microbial cells containing aspartase to produce an immobilized aspartase; feeding an ammonium fumarate solution into a reactor filled with the immobilized aspartase; and recovering the produced L-aspartic acid from the reaction mixture, wherein the immobilized aspartase has an activity of 250 U or more, and wherein the ammonium fumarate solution is fed into the reactor at the feed rate LHSV of 2 to 35.

Abstract: The present specification relates to a DNA comprising a nucleotide sequence coding for a polypeptide having ethylenediamine-N,N′-disuccinic acid:ethylenediamine lyase activity, the polypeptide having the amino acid sequence of SEQ ID NO: 1 which may have a deletion, substitution or addition of at least one amino acid; a recombinant plasmid containing the DNA; a host transformed with the recombinant plasmid; and a method for producing a diaminoalkylene-N,N′-disuccinic acid using the transformed host. The present specification also relates to a polypeptide having ethylenediamine-N,N′-disuccinic acid:ethylenediamine lyase activity which has the amino acid sequence of SEQ ID NO: 1 that may have a deletion, substitution or addition of at least one amino acid.

Abstract: A process for producing crystalline L-aspartic acid is disclosed essentially consisting of the steps of preparing a mix solution containing fumaric acid, ammonia and an alkaline metal hydroxide, reacting the mix solution with aspartase to give a reaction solution containing L-aspartate and crystallizing L-aspartic acid out of the reaction solution, wherein a further amount of ammonia is added to the reaction solution containing L-aspartate and subsequently fumaric acid is added thereto to crystallize L-aspartic acid. The process can provide crystalline L-aspartic acid of high purity in a good workability without the need of any complicated steps.

Abstract: The present invention provides a process for producing an L-amino acid which comprises culturing in a nutrient medium a microorganism which is capable of producing the L-amino acid and which can not grow in a synthetic medium containing said L-amino acid as the sole nitrogen source in an amount of 5 mg/ml or below, allowing the L-amino acid to accumulate in the culture, and recovering the L-amino acid from the culture.

Abstract: 2-Aminopropane is used as the amine donor in the stereoselective synthesis of a chiral amine from a ketone with a transaminase. In a typical embodiment, (S)-1-methoxy-2-aminopropane is prepared by bringing methoxyacetone into contact with a transaminase in the presence of 2-aminopropane as an amine donor until a substantial amount of methoxyacetone is converted to (S)-1-methoxy-2-aminopropane and 2-aminopropane is converted to acetone. In a second embodiment, L-alanine is prepared by bringing pyruvic acid into contact with a transaminase in the presence of 2-aminopropane as an amine donor.

Abstract: This invention relates to a method for removing fumarase activity from a microorganism or processed product thereof having ethylenediamine-N,N'-disuccinic acid ethylenediamine lyase activity, which includes treating the microorganism or processed product thereof with an aqueous alkaline solution at a pH of 8.0 to 10.5 in the presence of at least one salt with a concentration of 5 mM to 1000 mM. The salt is preferably selected from the group consisting of sodium, potassium, ammonium and C.sub.2-6 alkanediamine salts of boric acid, phosphoric acid, hydrochloric acid, sulfuric acid, acetic acid, oxalic acid, fumaric acid, maleic acid and ethylenediamine-N,N'-disuccinic acid, and mixtures thereof.

Abstract: The invention provides a process for the preparation of aspartic acid via a fermentation process for the preparation of ammonia fumarate, wherein the pH of the fermentation broth is controlled by the addition of a calcium base to produce a calcium fumarate precipitate, characterized in that ammonium fumarate is produced by separating the precipitated calcium fumarate from the fermentation broth, and reacting the same with a reagent selected from ammonia, ammonium carbonate, ammonia in combination with CO.sub.2 and mixtures therefore, to form ammonium fumarate and a co-product selected from calcium carbonate and calcium hydroxide, wherein the energy of indirect neutralization of fumaric acid by ammonia serves as the driving force for the conversion of calcium fumarate to the desired ammonium fumarate product and for the regeneration of a calcium base reagent, and wherein diammonium fumarate is enzymatically converted to ammonium aspartate and acidulated to from aspartic acid.

Abstract: Disclosed is a process for preparing acylated amino esters and a process for preparing optically active amino esters from racemic amino esters with a carboxylic ester as acylating agent, whose acid component has a halogen, nitrogen, oxygen or sulfur atom neighboring the carbonyl carbon atom, in the presence of a hydrolase selected from the group of amidase, protease, esterase and lipase, and subsequent separation of the enantioselectively acylated amino ester from the non-acylated other enantiomer of the amino ester.

Abstract: Disclosed is a mutant aspartase comprising the amino acid sequence of a wild-type E. coli aspartase wherein the amino acid residue at one of positions 25, 123, 421 and 463 is substituted. Also disclosed is a process for preparing the above mutant aspartase.

Abstract: A protein such as an enzyme or antibody is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. A preferred protein is an enzyme such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease. Crosslinked enzyme crystals preferably retain at least 91% activity after incubation for three hours in the presence of a concentration of Pronase.TM. that causes the soluble uncrosslinked form of the enzyme to lose at least 94% of its initial activity under the same conditions. A preferred enzyme:Pronase.TM. ratio is 40:1. Enzyme crystals that are crosslinked may be microcrystals having a cross-section of 10.sup.-1 mm or less.

Abstract: Proteins such as enzymes and antibodies are immobilized by crosslinking crystals of the proteins such as microcrystals having a cross-section of 10.sup.-1 mm or less with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. Crystals of an enzyme such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease may be crosslinked to provide crosslinked enzyme crystals that retain at least 91% activity after incubation for three hours in the presence of a concentration of Pronase.TM. that causes the soluble uncrosslinked form of the enzyme to lose at least 94% of its initial activity under the same conditions. A preferred Pronase.TM.:enzyme ratio is 1:40.

Abstract: A process for producing an optically active aminopolycarboxylic acid, such as S,S-ethylenediamine-N,N'-disuccinic acid, from a mixture of a diamine, such as ethylenediamine, with fumaric acid using a microorganism having a lyase activity, wherein at least one metal ion selected from the group consisting of an alkaline earth metal, iron, zinc, copper, nickel, aluminum, titanium and manganese is added to the reaction system. According to this process, aminopolycarboxylic acids, such as S,S-ethylenediamine-N,N'-disuccinic acid, or metal complexes thereof, can be appropriately and efficiently produced while improving the reaction yield.

Abstract: A protein such as an enzyme or antibody is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. A preferred protein is an enzyme such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease. Crosslinked enzyme crystals preferably retain at least 91% activity after incubation for three hours in the presence of a concentration of Pronase.TM. that causes the soluble uncrosslinked form of the enzyme to lose at least 94% of its initial activity under the same conditions. A preferred enzyme:Pronase.TM. ratio is 1:40. Enzyme crystals that are crosslinked may be microcrystals having a cross-section of 10.sup.-1 mm or less.

Abstract: The invention provides a process for the preparation of aspartic acid via a fermentation process for the preparation of ammonium fumarate, wherein the pH of the fermentation broth is controlled by the addition of a calcium base to produce a calcium fumarate precipitate, characterized in that ammonium fumarate is produced by separating the precipitated calcium fumarate from the fermentation broth, and reacting the same with a reagent selected from ammonia, ammonium carbonate, ammonia in combination with CO.sub.2 and mixtures thereof, to form ammonium fumarate and a co-product selected from calcium carbonate and calcium hydroxide, wherein the energy of indirect neutralization of fumaric acid by ammonia serves as the driving force for the conversion of calcium fumarate to the desired ammonium fumarate product and for the regeneration of a calcium base reagent, and wherein diammonium fumarate is enzymatically converted to ammonium aspartate and acidulated to from aspartic acid.

Abstract: Enzyme-containing cells are immobilized on a water-insoluble support with a polymer represented by the following general formula (I): ##STR1## wherein Y is a direct bond or a divalent group represented by the following formula (II) ##STR2## R.sub.1 and R.sub.2 are each independently hydrogen atoms or organic residues, X.sup.- represents an anion, and n is an integer of 100 to 5000. The support may be in granular form such as granules of ion exchange resins or inorganic carriers, or in sheet form such as ion exchange films or alumina or silica sheets. Immobilization may be carried out by mixing cells with water and a quaternary salt of polyallylamine as the polymer, and sprinkling the resultant mixture onto the solid support and drying. L-aspartic acid or fumaric acid can be produced by contacting fumaric acid and ammonia, or ammonium fumarate, or maleic acid and ammonia, or ammonium maleate, with immobilized cells containing aspartase or maleate isomerase.

Abstract: An improved process for preparing L-aspartic acid by enzyme-catalyzed reaction of fumaric acid with ammonia, in which, after reaction has been completed, excess ammonia is removed from the reaction mixture, L-aspartic acid is precipitated by adding acetic acid or formic acid, whereupon formic acid and acetic acid are rereleased from the mother liquor by adding fumaric acid, and the ammonia released and the liberated formic or acetic acid and the ammonium fumarate formed in the liberation are reused for subsequent cycles.

Abstract: The regioselective and chemoselective hydrolysis of an .alpha.-ester group of an amino acid diester using pig liver esterase enzyme (PLE) is disclosed. The amino acid diesters may be either N-protected or unprotected and the diester groups may be the same or different. In particular, the preparation of a number of .gamma.-ester glutamates and .beta.-ester aspartates are provided.

Abstract: The present invention provides a process for producing an L-amino acid which comprises culturing in a nutrient medium a microorganism which is capable of producing the L-amino acid and which can not grow in a synthetic medium containing said L-amino acid as the sole nitrogen source in an amount of 5 mg/ml or below, allowing the L-amino acid to accumulate in the culture, and recovering the L-amino acid from the culture.

Abstract: Disclosed are a process for producing aspartase which comprises culturing a microorganism belonging to the genus Escherichia being capable of producing aspartase in a medium until aspartase is produced and accumulated in the culture, and recovering aspartase therefrom, wherein dissolved oxygen concentration of the medium is in the range of 0 to 1 ppm on the stage that microbial growth is middle and/or late logarithmic growth phase; and a process for producing L-aspartic acid which comprises converting fumaric acid and ammonia into L-aspartic acid in an aqueous medium in the presence of an enzyme source, wherein said enzyme source is a culture produced in accordance with said aspartase-producing process, cells isolated from the culture, or processed cells thereof.

Abstract: A process for the preparation of disodium Z-L-aspartate from fumaric acid, in whicha) fumaric acid is reacted with ammonia in an inert diluent in the presence of aspartase or aspartase-producing microorganisms to give ammonium L-aspartate thenb) the ammonium L-aspartate-containing solution is treated with sodium hydroxide, forming, depending on the amount of sodium hydroxide used, the mono- or disodium L-aspartate or a mixture thereof, andc) the eliminated ammonia is returned to a fumaric acid suspension, which is used as starting solution for further enzymatic reactions, and thend) the residual mono and/or disodium L-aspartate-containing solution is reacted with benzyloxycarbonyl chloride at a pH of between 9 and 14, with the simultaneous addition of sodium hydroxide, to form disodium Z-L-aspartate.

Abstract: A protein such as an enzyme or antibody is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. A preferred protein is an enzyme such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease. Crosslinked enzyme crystals preferably retain at least 91% activity after incubation for three hours in the presence of a concentration of Pronase.TM. that causes the soluble uncrosslinked form of the enzyme to lose at least 94% of its initial activity under the same conditions. A preferred enzyme:Pronase.TM. ratio is 1:40. Enzyme crystals that are crosslinked may be microcrystals having a cross-section of 10.sup.-1 mm or less.

Abstract: A method of producing L-amino acids by fermentation. Microorganisms of the genus Corynebacterium which exhibit an auxotrophy relative to an amino acid are used as biocatalysts. The method is characterized in that the carbon source on the one hand and the limiting amino acid on the other hand are fed in two or more different infeed currents to the process. The infeed profiles have, for example, a concave (saccharose) and an exponential (amino acid) form or a convex (saccharose) and likewise a convex (amino acid) form, with specific differing degrees of increase of the currents relative to each other over time.

Abstract: A process and composition for preparing D-aspartic acid and .beta.-alanine from D,L-aspartic acid, wherein a solution of D,L-aspartic acid or a salt thereof is contacted with a composition having an L-aspartate-.alpha.-decarboxylase activity of greater than 100 .mu.mol L-aspartate used per hour per gram of cells, under appropriate conditions to produce D-aspartic acid and .beta.-alanine.

Abstract: An aminopeptidase is provided which efficiently decomposes a low-molecular-weight peptide containing glutamic acid or aspartic acid in its sequence. A method of hydrolyzing a peptide or protein by use of the aminopeptidase is also provided. Aminopeptidase GX is derived from germinated soybean cotyledons and releases glutamic acid or aspartic acid from a peptide or protein containing glutamic acid or aspartic acid at the N-terminal end and is used to hydrolyse peptides or proteins.

Abstract: A protein such as an enzyme or antibody is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent such as glutaraldehyde, and if desired lyophilizing the crosslinked crystals for storage. Crosslinking of the protein crystals provides stabilization for use under harsh conditions and for lyophilizing. The crystals crosslinked may be microcrystals having a cross-section of 10.sub.-1 mm or less. Crosslinked thermolysin, esterase, elastase, asparaginase and lysozyme crystals and crosslinked crystals of lipase from Geotrichum candidum and Candida cylindracea and of porcine origin can be used to convert a substrate to a product. Crosslinked thermolysin crystals are prepared that retain at least 96% of their initial activity after incubation for 4 days in the presence of a concentration of Pronase.TM. such as a thermolysin:Pronase.TM.

Abstract: Fumaric acid is produced by reacting a culture of a microorganism which produces maleate isomerase that exhibits a maximum activity at not less than 50.degree. C. or a treated product thereof with maleic acid in an aqueous solution, and isomerizing maleic acid to produce fumaric acid. L-aspartic acid is produced by reacting both of a culture of a microorganism which produces maleate isomerase or a treated product thereof and a culture of a microorganism which produces aspartase or a treated product thereof with maleic acid and ammonia in an aqueous solution, producing L-aspartic acid from maleic acid and ammonia by enzyme reactions, and recovering L-aspartic acid from the reaction mixture.

Abstract: A computer system chassis, including a base and a cover, implements an improved grounding system by integrally forming a plurality of flexible protruding contacts into predetermined contact regions throughout the base during the metal punching manufacturing phase of the chassis base blank. In this way, when the base and cover are attached to each other, the size of any gaps which may form in these contact regions, as a result of warpage or design tolerances, are reduced. This is due to the number of mechanical contacts being made by the plurality of flexible contacts which protrude and extend across these gaps and connect the base to the cover. In addition to reducing the size of these gaps, the flexible contacts provide an improved electrical grounding to the cover by increasing metal-to-metal contact between the cover and the base, both of which reduce EMI emissions from the computer system chassis.

Abstract: The regioselective and chemoselective hydrolysis of an .alpha.-ester group of an amino acid diester using pig liver esterase enzyme (PLE) is disclosed. The amino acid diesters may be either N-protected or unprotected and the diester groups may be the same or different. In particular, the preparation of a number of .gamma.-ester glutamates and .beta.-ester aspartates are provided.

Abstract: L-aspartic acid is produced by repeating the following respective steps:(1) a reaction step of producing ammonium L-aspartate from an aqueous solution containing monoammonium maleate in accordance with an isomerization reaction and an enzyme reaction caused by aspartase in the presence of ammonia;(2) an ammonia-eliminating step of converting substantially all produced ammonium L-aspartate into monoammonium salt by distilling or stripping a reaction solution obtained in the step (1);(3) a crystallization step of crystallizing L-aspartic acid and producing monoammonium maleate from a solution obtained in the step (2) by adding maleic acid, maleic anhydride or both;(4) a solid-liquid separation step of separating L-aspartic acid crystals precipitated in the step (3) from a mother liquor containing monoammonium maleate; and(5) a recycle step of supplying the mother liquor containing monoammonium maleate obtained in the step (4) to the step (1) to be used as a raw material for the reaction.

Abstract: The present invention relates to materials and methods for production of natural and unnatural D-amino acids. In particular, the present invention relates to a fermentation method for the production of D-amino acids using recombinant host cells.Specifically, the invention relates to a method for producing a D-amino acid in a cell, comprising:(a) incorporating into the cell a D-aminotransferase gene and a L-aminodeaminase gene;(b) culturing the cell in a cell culture medium; and(c) isolating the D-amino acid from the cell culture medium.The invention also relates to a method for producing D-phenylalanine in a cell, comprising:(a) incorporating into the cell a D-aminotransferase gene, a L-aminodeaminase gene and means for increasing production of phenylpyruvate;(b) culturing the cell in a cell culture medium; and(c) isolating the D-phenylalanine from the cell culture medium.The invention also relates to the preparation of recombinant cells for use in the production of enantiomerically pure D-amino acids.

Abstract: A process for the production of an extracellular peroxidase using confectionery waste is disclosed. The first step of the process requires culturing a piece of plant tissue containing extracellular peroxidase-producing cells from a plant of the genus Acer, more specifically Acer pseudoplantanus. The culture medium is a solid culture medium and the culturing step is carried out until a callus forms on the solid culture medium. Further, the plant cells produced in the callus are dispersed into a liquid culture medium to form a suspension of plant cell culture. The suspension culture medium contains confectionery waste products which provide 1 to 15% by weight of sugars (i.e. fructose, glucose and sucrose). The culturing of the plant cells in suspension in the liquid culture medium with the concomitant accumulation of the extracellular peroxidase in the liquid culture medium and separating the enzyme therefrom.

Abstract: DSM 9771 is a mutant of DSM 7330 which was obtained under selective pressure. Its enzymatic activity is higher by a factor of 2.3 than that of its parent organism. In the presence of an inducer, this activity may be farther increased by a factor of 2.7. The reaction catalyzed by this microorganism or enzymes therefrom is the enantioselective conversion of a D-5-monosubstituted hydantoin or an L-5-monosubstituted hydantoin or a D-N-carbamoyl amino acid or an L-N-carbamoyl amino acid to a corresponding L-.alpha.-amino acid.

Abstract: A method of producing an optically active amino acid is disclosed which comprises converting a mixture of an amino group-containing compound, e.g., an alkanediamine, and fumaric acid into an optically active amino acid by the action of a microorganism. The method is useful in industrially producing an optically active amino acid from the inexpensive starting materials, i.e., fumaric acid and an amino compound, under mild conditions of ordinary temperature and ordinary pressure.

Abstract: Fumaric acid is produced by reacting maleic acid in an aqueous solution with a microorganism which has maleate isomerase activity or with a preparation from the microorganism having the maleate isomerase activity, and producing fumaric acid in a reaction solution by enzymatic isomerization of maleic acid carried out under the condition that the dissolved oxygen concentration in the reaction solution is substantially maintained at 4 ppm or less, for example, by sealing the reaction solution with one or more gases selected from N.sub.2, Ar, and He.

Abstract: A protein such as an enzyme of antibody is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. A preferred protein is an enzyme such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease. Crosslinked enzyme crystals preferably retain at least 91% activity after incubation for three hours in the presence of a concentration of Pronase.TM. that causes the soluble uncrosslinked form of the enzyme to lose at least 94% of its initial activity under the same conditions. A preferred enzyme:Pronase.TM. ratio is 1:40. Enzyme crystals that are crosslinked may be microcrystals having a cross-section of 10.sup.-1 mm or less.

Abstract: A process for production of L-aspartic acid comprising the steps of (1) contacting (A) an enzyme-containing material having maleate isomerase activity and aspartase activity, or (B) an enzyme-containing product having maleate isomerase activity and an enzyme-containing material having aspartase activity, with a substrate solution containing maleic acid and ammonia, and/or ammonium maleate to form L-aspartic acid, and (2) recovering L-aspartic acid from the reaction solution, characterized by adding maleic anhydride and/or maleic acid to the reaction solution to crystallize L-aspartic acid, and (3) recycling the mother liquors as the substrate solution by addition of ammonia.

Abstract: The treatment of blood and other body fluids and tissues, the detection of tumors and the treatment of patients is disclosed. The treatment and detection involve the use of families of chlorins, families of purpurins and families of metal complexes of chlorins and purpurins. The purpurins and their metal complexes have the structures of FIGS. 1 , 7, 14-18, 29-38, 44-48 and 54-58 of the attached drawings. The chlorins and their metal complexes have the formulas of FIGS. 2 , 8, 19, 20, 22, 23, 24, 25, 27, 28, 39, 40, 42, 43 and 49-53 of the attached drawings. Solutions of the purpurins, of the foregoing and other chlorins and of the metal complexes which are physiologically acceptable for intravenous administration are also disclosed, as are emulsions or suspensions of the solutions. The solvent for the solutions can be a product of the reaction of ethylene oxide with castor oil.

Abstract: L-aspartic acid is improvedly prepared in high yields by treating ammonium aspartate, advantageously in aqueous reaction medium, with an effective, aspartic acid-precipitating amount of fumaric acid.

Abstract: A hapten is described which may be used to elicit antibodies that catalyze the deamidation of asparginyl-glycyl dipeptides to form two products, the isoaspartyl-glycyl dipeptide and the aspartyl-glycyl dipeptide. A general synthetic scheme is also presented which shows how to modify the hapten to provide specificity for a particular protein in the antibodies that are elicited by the (modified) hapten. Antibodies which catalyze the the deamidation reaction are also described.

Abstract: A toner comprised of pigment, and a polyimide-imine resin of the formula ##STR1## wherein m, and n represent the number of monomer segments; X is independently selected from the group consisting of a tetravalent aromatic, polyarylomatic or cycloaliphatic group with from about 6 to about 20 carbon atoms and a cycloaliphatic group; R is independently selected from the group consisting of alkylene, oxyalkylene and polyoxyalkylene; and R' is independently selected from the group consisting of alkyl, alkylene and arylene.

Abstract: An aminopeptidase is provided which efficiently decomposes a low-molecular-weight peptide containing glutamic acid or aspartic acid in its sequence. A method of hydrolyzing a peptide or protein by use of the aminopeptidase is also provided. Aminopeptidase GX is derived from germinated soybean cotyledons and releases glutamic acid or aspartic acid from a peptide or protein containing glutamic acid or aspartic acid at the N-terminal end and is used to hydrolyse peptides or proteins.