Continuous Fermentation Process is the process in which cells are maintained in continuous culture in the exponential growth phase by the frequent addition of fresh medium that is exactly balanced by the removal of cell suspension from the bioreactor.
Some of the processes patented in USPTO are given below.
Patent no: 5,962,046 titled ‘Continuous fermentation process’ with the abstract: Process for the continuous preparation of a fermented milk in which (1) a milk fermented by lactic acid bacteria is prepared in a first device, the fermented milk being subjected to stirring and pH conditions such that syneresis of the milk does not occur, the pH being regulated by the continuous addition of unfermented milk to the first device and continuously drawing off fermented milk from the first device; (2) in a second, post-acidification device, the fermented milk drawn off from the first device is cooled to a temperature of less than 15.degree. C. so as to subject the fermented milk to a post-acidification, the residence time of the fermented milk in the second device being adjusted so that at the outlet of the latter, the pH of the fermented milk is less than pH 4.7; and (3) a fermented milk having a pH of less than pH 4.7 is continuously drawn off from the second device.
Patent no: 5,925,563 titled ‘Multi-stage column continuous fermentation system’ with the abstract: A multi-stage column continuous fermentation system for brewing beer and the like. The system comprises several basic interconnected stages or sections including a discharge stage or section, a feed stage, at least one fermentation stage, a top stage, and a CO.sub.2 discharge column. The discharge section functions in waste and yeast collection and discharge. The feed stage functions as a means of inputting wort from the initial stages of the brewing process. Each fermentation stage functions in fermentation and CO.sub.2 gas bubble collection and discharge. In certain types of brew, this example included, more than one fermentation stage may be needed or desired. Additional fermentation and CO.sub.2 collection takes place along the added vertical space provided by each additional stage. An optional isolation stage or section may be added for certain types of brew where the brew requires cooling during ascension. Finally, in the top section, the brew is clarified and output to known filtering, aging, carbonation and/or dispensing sections or apparatus depending upon the particular style of brew processed.
Patent no: 6,878,534 titled ‘Continuous fermentation process which is useful for the simultaneous optimal production of propionic acid and vitamin B12’ with the abstract: The present invention relates to a fermentation process which is useful for the simultaneous production of propionic acid and vitamin B.sub.12, characterized in that it employs the culturing, on a suitable culture medium, of at least one microorganism suitable for the production of vitamin B.sub.12 and propionic acid, and in that the corresponding fermentation is carried out in continuous fashion and involves at least two successive stages, a first stage associated with the optimal production of propionic acid, and a second with the optimal production of vitamin B.sub.12.