ISSN:
0006-3592
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The rate of dissolution and dehydration of CO2 in a liquid model system was investigated. Components in the model system established the main conditions which may exist, in the extracellular space of a microbiological culture liquid. The charge in voltage of a glass electrode was measured which indicated the formation of H+ ions in the H2CO3 ⇌ HCO3- H+ reaction. The rate of CO2 hydration increased with the increase of temperature from 0 to 40°C. Likewise the equilibrium of the reaction was shifted towards the forward reaction. Similar results were observed when the tip velocity of the impeller was increased. Data suggest that agitation promotes the dissolution of CO2 in the culture liquid through the reduction of gas-liquid film resistance in the diffusion of this gas. The rate of hydration of CO2 into the bulk of the liquid was independent of pCO2 above the surface of the liquid but depended on pCO2 in the gas bubble within the liquid. The concentration of HCO3- was, furthermore, influenced by the buffer components, buffer capacity, and the viscosity of the system. Since pCO2 and the HCO3- concentration in the extracellular space depend on both physical and chemical factors, the ventilation of a culture liquid necessitates both exhaust of CO2 from the gas bubbles of the culture broth and shift of the H2CO3 ⇌ HCO3- + H+ reaction towards the backward direction.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260100203
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