ISSN:
0006-3592
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The oxygen demand of Penicillium chrysogenum culture was supplied by an automatic aeration control system on the basis of the actual respiration of the cells. The simultaneous use of the automatic aeration apparatus and a turbomixer of great shear stress revealed that some effects of agitation are independent of aeration. These effects of agitation are manifested in two ways: (1) in the increased break down of the cell clumps, thus assuring large free cell surfaces for contact with the substrates; and (2) in the increased mixing effect, which assures a continuous mass transfer towardes the free cell surfaces. These effects of the agitation can improve the yield when the O2 level is maintained near to the saturation value. By means of an automatic aeration control system, the influence of carbon dioxide on the metabolism of hyphae and the production of penicillin was found to be demonstrably inhibitory when the dissolved oxygen was above the critical concentration in the culture liquid. This result is supporting evidence for the assumption that aeration is necessary to biosynthetic processes in two equally important ways: (1) to maintain the oxygen level above the critical value; and (2) to assure ventilation, by which the carbon dioxide level may be kept below its inhibitory critical value.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260070304
