Abstract: A process for preparing an immobilized microorganism which comprises cultivating a microorganism in a culture broth, treating the broth with glutaraldehyde when cultivation being completed, collecting microbial cells from the broth, admixing the microbial cells with an aqueous solution of a polysaccharide having 10 w/w % or more of sulfate moiety in the molecule thereof and then gelling the polysaccharide in the resulting mixture to entrap the microbial cells within the gel matrix of the polysaccharide. The process is suitable for the industrial preparation of immobilized microorganisms.

Abstract: .alpha.-(S)-amino acid..alpha.-phenylethanesulfonate compounds and methods of optical resolution of .alpha.-amino acids and .alpha.-phenylethanesulfonic acids are described.

Abstract: At least one acryl or allyl monomer is polymerized in an aqueous suspension containing a fumarase-producing microorganism. The resultant immobilized fumarase-producing microorganism is contacted with bile acids or salts thereof. Then, the immobilized fumarase-producing microorganism is subjected to enzymatic reaction with fumaric acid or a salt thereof. L-Malic acid is prepared without the production of the by-product succinic acid.

Abstract: An improved method for the fermentative production of L-threonine in a high yield, which comprises cultivating a methionine metabolism-antagonist resistant mutant of Serratia marcescens having L-threonine productivity in a broth to form and accumulate L-threonine therein and recovering accumulated L-threonine from the broth.

Abstract: A method for the fermentative production of L-proline which comprises cultivating a L-proline-producing mutant of a microorganism belonging to the genus Serratia in a broth to produce and accumulate L-proline therein and collecting accumulated L-proline. The mutant is preferably that of Serratia marcescens which is deficient in L-proline oxidase and is resistant to proline analong under a high osmotic pressure.

Abstract: Novel di-L-cysteine L-malate of the formula:[HS--CH.sub.2 --CH(NH.sub.3).sup.+ --COOH].sub.2.(.sup.- OOC--CHOH--CH.sub.2 --COO.sup.-)which has excellent storage stability and excellent pharmacological activities and is useful for the preparation of the amino acid infusion solutions, and process for the preparation of the di-L-cysteine L-malate by reacting 2 moles of L-cysteine L-malate and more than 0.9 mole of L-malic acid in an aqueous medium and collecting the resulting crystalline di-L-cysteine L-malate.

Abstract: The present invention relates to the optical resolution of a p-hydroxyphenylglycine salt with simultaneous racemization of the undesired enantiomer thereof. The invention is carried out by preferential crystallizing out the desired enantiomer from a supersaturated solution of the racemic modification thereof in a lower aliphatic acid in the presence of an aliphatic or aromatic aldehyde.

Abstract: An immobilized enzymatic active substance having an improved stability of enzymatic activity is prepared which comprises an enzymatic active substance such as microbial cells entrapped within a gel matrix of an unsubstituted amino, monoalkylamino or dialkylamino group-introduced polysaccharide having not less than 10 w/w % of sulfate moiety in the molecule thereof such as carrageenan. The immobilized enzymatic active substance is prepared by admixing the enzymatic active substance and an aqueous solution of the polysaccharide and then allowing to form a gel of the polysaccharide.

Abstract: A novel crystalline salt of a basic L-amino acid with L-malic acid, particularly a neutral crystalline salt consisting of 2 moles of L-lysine, L-ornithine or L-arginine with 1 mole of L-malic acid, which have no bitter taste and can be administered by oral route as a nutritive supplement or as a medicine, and further contain no chloride ion and hence are useful for preparing an infusion solution with no undesirable side effect due to chloride ion.

Abstract: p-Hydroxyphenylglycine..alpha.-phenylethanesulfonate which is useful for the production of optically active p-hydroxyphenylglycine and optically active .alpha.-phenylethanesulfonic acid is disclosed. p-Hydroxyphenylglycine..alpha.-phenylethanesulfonate is produced by either reacting DL-p-hydroxyphenylglycine with optically active .alpha.-phenylethanesulfonic acid or reacting (.+-.)-.alpha.-phentylethanesulfonic acid with optically active p-hydroxyphenylglycine to form two diastereomers of DL-p-hydroxyphenylglycine optically active .alpha.-phenylethanesulfonate or optically active p-hydroxyphenylglycine (.+-.)-.alpha.-phenylethanesulfonate, and isolating one diastereomer according to the difference between solubilities of the diastereomers, optionally, combining selective crystallization of one diastereomer and epimerization of another diastereomer in the case of reaction of DL-p-hydroxyphenylglycine and optically active .alpha.-phenylethanesulfonic acid.

Abstract: DL-.alpha.-amino acids or a salt thereof can be obtained by racemizing an optically active .alpha.-amino acid or a salt thereof in the presence of an aliphatic acid and an aldehyde.

Abstract: An immobilized aminoacylase is prepared by bonding aminoacylase to a water-insoluble porous anion exchanger such as a porous phenolic resin, porous styrene resin, porous silica or porous glass having anion exchange groups and treating the bonded amino-acylase with a crosslinking agent such as an aliphatic dialdehyde. The porous anion exchanger preferably has a pore size of about 150.degree. to 3,000 A.degree., pore volume of about 0.3 to 1.0 m.sup.1 /g, specific surface area of about 10 to 150 m.sup.2 /g and particle size of above 0.1 to 1.2 mm. Preferred anion exchangers are trimethylammonium-introduced styrene resin and trimethylammonium-introduced silica.

Abstract: A method for removing a pyrogen from a solution of a pyrogen-containing substance such as an amino acid, a nucleic acid base, an antibiotic, a hormone, a vitamin, an enzyme, an antibody or the like comprising contacting the solution with an adsorbent to adsorb the pyrogen, which is characterized in that the adsorbent comprises a water-insoluble carrier and a nitrogen-containing heterocyclic compound of the formula:R--A--Xwherein R is a nitrogen-containing heterocyclic group; A is single bond, alkylene or alkenylene; X is hydrogen or a functional group; and the heterocyclic group and alkylene may be optionally substituted by one or more substituents, and the compound being bonded to the carrier directly or through a spacer.

Abstract: Ethanol is produced in high concentration of 75 mg/ml or above such as 200 mg/ml by using an immbolized ethanol-producing microorganism to convert sugar to ethanol in a nutrient culture broth containing not more than 100 mg/ml sugar until the concentration of sugar is not more than 20% of its initial concentration, then adding a fresh culture broth containing not less than 100 mg/ml sugar and converting sugar to ethanol with the immobilized microorganism to produce the desired high concentration of ethanol. The microorganism is preferably immobilized in a sulfated polysaccharide gel as a dense layer near the surface of the gel.

Abstract: Seed crystals of an optically active enantiomer of any one of p-hydroxyphenylglycine benzenesulfonate, p-hydroxyphenylglycine p-ethylbenzenesulfonate, p-hydroxyphenylglycine o-toluenesulfonate or p-hydroxyphenylglycine sulfosalicylate are added to a supersaturated solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt. Crystallization of the optically active enantiomer results. Then, the crystals are recovered. Alternatively, crystals of the optically active enantiomer may be added to a hot solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt to produce a supersaturated solution thereof. The solution is then cooled to crystallize out the optically active enantiomer. Optically active p-hydroxyphenylglycine benzenesulfonate, optically active p-hydroxyphenylglycine p-ethylbenzenesulfonate, optically active p-hydroxyphenylglycine o-toluenesulfonate or optically active p-hydroxyphenylglycine sulfosalicylate is thereby obtained.

Abstract: An immobilized aminoacylase preparation is obtained by adsorbing tannin on a water-insoluble, hydrophilic carrier to give a water-insoluble tannin preparation, adsorbing aminoacylase on the tannin preparation to give a water-insoluble tannin-aminoacylase preparation, and then binding ferric or ferrous ion thereto. The immobilized preparation obtained above sustains a high rate of enzymatic activity for a long period of time when used in an enzymatic reaction thereof with N-acyl-DL-amino acids.

Abstract: An aqueous solution of crude urokinase is contacted with a cross-linked diethylaminoethyl-agarose to have pyrogens adsorbed thereon. The effluent is then contacted with a water-insoluble, hydrophilic polysaccharide having a group of the formula:--CH.sub.2 CH(OH)CH.sub.2 Rwherein R is sulfothio, sulfo or p-sulfophenylamino, and the urokinase adsorbed is eluted from said polysaccharide. Pyrogen-free urokinase is thereby obtained in a high purity as the eluate.

Abstract: An enzyme or microorganism is entrapped within the gel matrix of a sulfated polysaccharide (said polysaccharide containing more than 10 w/w% of a sulfate moiety in its molecule) in the presence of ammonium ion, a metal ion, a water-soluble amine or a water-miscible organic solvent. The immobilized enzyme or microorganism thus obtained shows a high level of catalytic activity for a long period of time and can be used for continuous enzymatic reactions with substrates.

Abstract: An aqueous solution of L-malic acid and potassium ion is prepared having a pH of no more than 6.8. The aqueous solution is cooled to initiate crystallization of a potassium salt of L-malic acid, and the aqueous mixture obtained is allowed to stand at a pH of 5.3 to 6.8 until it substantially reaches liquid-solid equilibrium. The resultant crystals of monopotassium L-malate monohydrate are collected therefrom. The monopotassium L-malate monohydrate thus obtained may be dried to give the corresponding anhydrate. Monopotassium L-malate and its monohydrate are stable, non-hygroscopic crystals.

Abstract: A water-insoluble tannin preparation is obtained by covalent binding or physical adsorption of tannin onto a water-insoluble, hydrophilic carrier. The preparation has a specific affinity for proteins and can be used as an adsorbent for purification, isolation and/or separation of proteins (e.g., Enzymes, albumin, globulin, hormonal proteins) from a mixture of compounds. Further, the water-insoluble tannin preparation having a catalytically active enzyme absorbed thereon can be used as a heterogeneous catalyst to induce enzymatic reactions.