Abstract: Provided is a method for refining quinolinic acid, including the steps of: preparing a fermentation solution including at least one of quinolinic acid and a salt thereof; removing microbial cells from the fermentation solution; preparing an acidic composition containing at least one of quinolinic acid and a salt thereof at a saturation concentration or more by adding an acid to the fermentation solution; and recovering a crystal of least one of quinolinic acid and a salt thereof from the acidic composition.

Abstract: A method comprising: (a) enzymatically processing an O-acetylhomoserine (OAHS) fermentation liquor to produce L-methionine and an acetate source; (b) separating at least a portion of said L-methionine from at least a fraction of said acetate source to form separated L-methionine and a residual liquor comprising an acetate-source; and (c) recovering at least a portion of said acetate source from said residual liquor as recovered acetate.

Abstract: A purification method of 1,4-diaminobutane, 1,4-diaminobutane purified using the purification method, and a polyamide prepared using the purified 1,4-diaminobutane are provided. The purification method of 1,4-diaminobutane includes: concentrating a fermentation solution including at least one of 1,4-diaminobutane and a salt thereof to obtain a concentrate; adding a base to the concentrate of the fermentation solution to prepare an basic composition having a pH 12 or higher; and recovering 1,4-diaminobutane from the basic composition.

Abstract: The present invention relates to a polynucleotide that is active to an acetyl glutamate synthase and acetyl ornithinase which are associated with ornithine or arginine biosynthesis from Corynebacterium glutamicum. The present invention also relates to a polypeptide encoded by said polynucleotide, a recombinant vector comprising said polynucleotide, to a transformant obtained by introducing said recombinant vector to a host microorganism for producing L-ornithine or L-arginine, and transforming the recombinant vector, and to a method for producing L-ornithine or L-arginine by culturing said transformant. The activity of the transformant of the present invention to an acetyl glutamate synthase and acetyl ornithinase is increased as compared to an intrinsic activity, and thus L-ornithine or L-arginine can be produced, at a high yield rate, from the transformant of the present invention.