Optimal conditions for gramicidin S production in continuous culture

✍ Scribed by H. W. Blanch; P. L. Rogers

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 687 KB
• Volume: 14
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260140202

✦ Synopsis

In the present study optimal policies have been evaluated for the production of gramicidin S in multistage continuous culture. An economic objective function was developed which took account of the number and size of the reaction vessels, the costs involved in antibiotic extraction, substrate costs, and variability in the selling price of gramicidin S. Optimal values of temperature and pH were 28.3 and 7.24, respectively, and independent of the stage in the system. Using the discrete maximum principle it was shown that a "cut-off" point existed for the selling price of the antibiotic below which production was no longer profitable. Furthermore it was established that beyond 3 stages in a multistage system, only marginal gains in profitability could be made (viz., an increase in 6.3% on going from a 3-stage to a 4-stage system).