The Isolation Of Resistant Mutants

The isolation of analogue-resistant mutants has already been discussed in the field of primary metabolism, where the rationale was that a mutant resistant to the inhibitory effects of an analogue, which mimics the control characteristics of the natural metabolite, may overproduce the natural metabolite. This approach has been adopted, or may be adopted, in a number of guises in the field of secondary metabolism. i Mutants may be isolated which are resistant to the analogues of primary metabolic...

Basic Functions Of A Fermenter For Microbial Or Animal Cell Culture

Fermenter Diagram

The main function of a fermenter is to provide a controlled environment for the growth of microorganisms or animal cells, to obtain a desired product. In designing and constructing a fermenter a number of points must be considered 1. The vessel should be capable of being operated aseptically for a number of days and should be reliable in long-term operation and meet the requirements of containment regulations. 2. Adequate aeration and agitation should be provided to meet the metabolic...

The Achievement And Maintenance Of Aseptic Conditions

Steam Trap Fermenter

Once the design problems of aeration and agitation have been solved, it is essential that the design meets the requirements of the degree of asepsis and containment demanded by the particular process being considered. It will be necessary to be able to sterilize, and keep sterile, a fermenter and its contents throughout a complete growth cycle. There may be also a need to protect workers and the environment from exposure to hazardous micro-organisms or animal cells Van Houten, 1992 . As has...

Whole Broth Processing

Whole Broth Processing

The concept of recovering a metabolite directly from an unfiltered fermentation broth is of considerable interest because of its simplicity, the reduction in process stages and the potential cost savings. It may also be possible to remove the desired fermentation product continuously from a broth during fermentation so that inhibitory effects due to product formation and product degradation can be minimized throughout the production phase Roffler et al., 1984 Diaz, 1988 . Bartels et al. 1958...

Other Fermentation Vessels

Mycoprotein Fermenter

Some of the other forms of fermentation vesels will now be considered. These vessels have more limited applications and have been developed for specific purposes or closely related processes. Some are historical developments, such as the earliest forms of packed tower, others were being developed in parallel with the standard mechanically stirred fermenter during the 1940s, while other approaches are more recent. Aspects of this topic have been reviewed by Prokop and Votruba 1976 , Katinger...

The Isolation Of Mutants Which Do Not Produce Feedback Inhibitors Or Repressors

Mutants which do not produce certain feedback inhibitors or repressors may be useful for the production of intermediates of unbranched pathways and intermediates and end products of branched pathways. Demain 1972 presented several 'blue-prints' of hypothetical mutants producing intermediates and end products of biosynthetic pathways and these are illustrated in Fig. 3.12. The mutants illustrated in Fig. 3.12 do not produce some of the inhibitors or repressors of the pathways considered and,...