The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 12, 1994
Filed:
Jul. 31, 1991
Toru Shinohara, Saga, JP;
Masaru Otani, Saga, JP;
Ajinomoto Co., Inc., Tokyo, JP;
Abstract
Optically active tryptophan of high purity can be obtained in high yields from a tryptophan fermentation broth, using crystallization of optically active tryptophan hydrochloride in combination with concurrent neutralization crystallization. According to the present invention, optically active tryptophan from a tryptophan containing fermentation broth, is carried out by (a) removing cells from the fermentation broth, adding hydrochloric acid, or a mixture of hydrochloric acid and an inorganic salt which contains chloride ions, to the cell-free broth to effect crystallization, (b) separating optically active tryptophan hydrochloride, (c) dissolving the optically active tryptophan hydrochloride, and (d) subjecting the resulting solution and an alkali solution to concurrent neutralization crystallization, maintaining a pH of the crystallization solution in the range of from 3 to 8.