Oxygen penicillin fermentation

In the present case there are seven flows, and Equ. 2.11 specifies four equations between the flows represented in the matrix of Equ. 1.8. Hence, only three flows are independent variables (cf. Sect. 1.2). Which kind of flows to be chosen for measurement depends on the possibilities for experimental determination. The knowledge, for example, of the respiratory quotient and the ratio of oxygen consumption to substrate consumption allows direct estimation of the biomass production rate and the product formation rate. This conclusion from the application of balancing is of the greatest importance in situations where process variables, for example, X, are very difficult to measure, which is the case in penicillin fermentation (Mou and Cooney, 1983). 

Vardar, F., and M. D. Lilly (1982). Effect of cycling dissolved oxygen concentrations on product formation in penicillin fermentations, Eur. J. Appl. Microbiol. Biotechnol., 14(4), 203-211. 

A typical fermentation medium for penicillin production contains lactose, com steep Hquot, and calcium carbonate (3,153,154). In most industrial processes the carbohydrate source, glucose, beet molasses, or lactose, is continuously added to the fermentation. The rate of glucose addition must be carefully monitored, by pH or rate of oxygen depletion, because the synthesis of penicillin is markedly reduced in the presence of excess glucose. 

If growth in the fermenter proceeds unchecked at the rate prevailing in the seed stages, the culture would become very dense and the available aeration would no longer be sufficient to maintain penicillin production. Should oxygen availability fall... 

In a multistage reaction penicillin G is nowadays produced exclusively by the aerobic submerged process, whereby oxygen is introduced by aerating the base of the reactor (fermenter) strains of the mold Penicillium chrysogenum are the predominantly used microorganism. 

Large scale fermenters are used to make such products as yeast, vitamin C, xanthan gum, citric acid, aud penicillin, for example. Fermentations are usually carried out in tall vessels with multiple-impeUer systems. Air is sparged in at the bottom to provide the microorganisms in the vessel with a supply of oxygen. It is important that the mixer disperse the gas into fine bubbles, a condition that is required to ensure good mass transfer from the air to the broth. See Chapter 11... 

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