Uptake rate

Sorption Rates in Batch Systems. Direct measurement of the uptake rate by gravimetric, volumetric, or pie2ometric methods is widely used as a means of measuring intraparticle diffusivities. Diffusive transport within a particle may be represented by the Fickian diffusion equation, which, in spherical coordinates, takes the form... 

Further efficient fermentative methods for manufacture of riboflavin have been patented one is culturing C. famata by restricting the carbon source uptake rate, thereby restricting growth in a linear manner by restriction of a micronutrient. By this method, productivity was increased to >0.17 g riboflavin/L/h (63). The other method, using Bacillus subtilis AJ 12644 low in guanosine monophosphate hydrolase activity, yielded cmde riboflavin 0.9 g/ L/3 days, when cultured in a medium including soy protein, salts, and amino acids (64). 

A plot of the specific respiration rate ( 02 versus the specific growth rate coefficient [L is linear, with the intercept on the ordinate equal to the oxygen uptake rate for cell maintenance. A formulation of this is ... 

Uptake rate = uptake for maintenance -t- uptake for growth... 

Uptake rate = maintenance uptake -t- growth uptake -t- product uptake... 

A tracing of the electrode signal during a cycle of turning aeration off and on is shown in Fig. 24-15. The rate of supply is zero (after bubbles have escaped) in the first portion of the response curve thus, the slope equals the uptake rate by the organisms. When aeration is resumed, both the supply rate and uptake rate terms apply. The values for C — C can be calculated from the data, the slope of the response curve at a given point is measured to get dC/dt, and the equation can be solved for K a because all the other values are known. 

A useful index of process performance is the oxygen uptake rate, OUR, that is calculated from the difference in oxygen concentration of the inlet air and the exiting gas. Also important is the respiration ratio defined as the carbon dioxide evolved divided by the oxygen consumed. 

HR-ICP-MS EEEMENT-2 (Pinnigan MAT, Germany) equipped with a standard introduction system (quartz water-cooled spray chamber, concentric nebulizer, torch with 1.5 mm i.d. injector and nickel cones) was used for measurements. The following operating conditions were used RP power 1150 W, coolant gas flow rate 16 1 min k auxiliary gas flow rate 0.85 1 min nebulizer gas flow rate 1.2 1 min k Sample uptake rate was 0.8-1 ml min k Measurements were performed with low and middle resolutions. Rh was used as an internal standard. Por calibration working standard solutions were prepared by diluting the multielemental stock solutions CPMS (SPEX, USA) with water to concentration range from 5 ng to 5 p.g I k... 

Livingston, A.G., Gikas, P., Viability of immobilised cells use of specific ATP levels and oxygen uptake rates.. Immobilised Cells Basics and Applications, Ed. Wijfells, R.H., Buitelaar, R.M., Bucke, C., Tramper, J., Progess in Biotech. 11, pp.264-271, 1996. 

Oxygen uptake rate (OUR) The actual rate at which oxygen utilization takes place and is given by ( o/Yo2) C, , where p is specific growth... 

Oxygen uptake Rate of oxygen transfer from air resident in the pulmonary... 

In biochemical engineering processes, measurement of dissolved oxygen (DO) is essential. The production of SCP may reach a steady-state condition by keeping the DO level constant, while the viable protein is continuously harvested. The concentration of protein is proportional to oxygen uptake rate. Control of DO would lead us to achieve steady SCP production. Variation of DO may affect retention time and other process variables such as substrate and product concentrations, retention time, dilution rate and aeration rate. Microbial activities are monitored by the oxygen uptake rate from the supplied ah or oxygen. 

A strain of Azotobacter vinelandii was cultured in a 15 m3 stirred fermenter for the production of alginate. Under current conditions the mass transfer coefficient, kLa, is 0.18 s. Oxygen solubility in the fermentation broth is approximately 8 X 10 3 kgm-3.9 The specific oxygen uptake rate is 12.5 mmol g 1 h. What is the maximum cell density in the broth If copper sulphate is accidentally added to the fermentation broth, which may reduce the oxygen uptake rate to 3 mmol g 1 h 1 and inhibit the microbial cell growth, what would be the maximum cell density in this condition ... 

Let us assume the solubility of oxygen does not affect on C or kLa, the factor affected on the oxygen uptake rate that is 12.5/3 = 4.167, then xmm is ... 

Gas holdup Inducers Specific oxygen uptake rate... 

Wang et al.2 and Najafpour et al.3A worked with immobilised microbial cells of Nitrobacer agilis, Saccharomyces cerevisiae and Pseudomonas aeruginosa in gel beads, respectively. They found separately that the cells retained more than 90% of their activity after immobilisation by using specific oxygen uptake rate (SOUR) [mg 02g 1 (dry biomass) h 11 as the biomass activity indicator. Such differences in immobilised biomass and activity between free and immobilised biomass activities depend strongly on the particular characteristics of the microbial systems and their interaction with the support matrix. 

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