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:
Mar. 20, 1990
Filed:
Aug. 01, 1988
Ho Nam Chang, Seoul, KR;
Bong Hyun Chung, Seoul, KR;
Abstract
Aspergillus niger B60 was immobilized in a dual hollow fiber bioreactor to produce citric acid continuously. The fungi proliferated well in the interstitial region formed by a parallel arrangement of three microporous polypropylene hollow fibers contained within a silicone tube. Excessive fungal cell growth could be controlled by supplying a nitrogen-deficient medium at the production stage, and also uniform cell distribution in the reactor could be obtained by changing the direction of medium flow. With pure oxygen aeration and nitrogen-deficient medium, volumetric productivity reached 1.62 g/l.h at a residence time of 4.02 h, which corresponded to a 27-fold increase over that of shake-flask fermentation. When the residence time was increased to 20.1 h, citric acid at a concentration of 26 g/l was continuously produced, with a yield of 80-90% and a volumetric productivity of 1.3 g/l.h. This represents a significant improvement in final concentration, yield and the volumetric productivity over the equivalent values of the corresponding batch formentation, which were 18 g/l, 40% and 0.06 g/l.h, respectively.