Consumption rate, oxygen

Contamination of the production vessel leads to serious financial penalties and each step in the inoculum train is monitored for contamination. To reduce the risk of contamination during sampling it is usual to take a sample from the residue left in each vessel after its contents have been transferred to the next reactor. Since these contamination checks are retrospective, a heavy reliance is placed on the growth characteristics of the production organism. Kinetic variables such as growth rate and oxygen consumption rate are also used to assess the quality of the inoculum. 

Transient computations of methane, ethane, and propane gas-jet diffusion flames in Ig and Oy have been performed using the numerical code developed by Katta [30,46], with a detailed reaction mechanism [47,48] (33 species and 112 elementary steps) for these fuels and a simple radiation heat-loss model [49], for the high fuel-flow condition. The results for methane and ethane can be obtained from earlier studies [44,45]. For propane. Figure 8.1.5 shows the calculated flame structure in Ig and Og. The variables on the right half include, velocity vectors (v), isotherms (T), total heat-release rate ( j), and the local equivalence ratio (( locai) while on the left half the total molar flux vectors of atomic hydrogen (M ), oxygen mole fraction oxygen consumption rate... 

Figure 2.27. Mixing, mass transfer and oxygen consumption in a bubble column bioreactor (Oosterhuis, 1984). Tj - reaction time constant, Xmt - ass transfer time constant, tmix -mixing time constant. ro2 - oxygen consumption rate, Vs - superficial gas velocity.

Hose, J.E. and H.W. Puffer. 1984. Oxygen consumption rates of grunion (Leuresthes tenuis) embryos exposed to the petroleum hydrocarbon, benzo[a]pyrene. Environ. Res. 35 413-420. 

Fig. 4.6 Oxygen consumption rates for BF4 or BF6 (35 pM) in presence of 1 mM NADH or 2mM histidine with or without 5 mM sodium azide in 1 3H20/DMS0 determined by ESR oximetry...

Reddy KR, Rao PSC, Patrick WH, Jr. 1980. Factors infiuencing oxygen consumption rates in flooded soils. Soil Science Society of America Journal 44 741-744. 

Steady-State Mass Balance Method In theory, the Ki a in an apparatus that is operating continuously under steady-state conditions could be evaluated from the flow rates and the concentrations of the gas and liquid streams entering and leaving, and the known rate of mass transfer (e.g., the oxygen consumption rate of microbes in the case of a fermentor). However, such a method is not practical, except when the apparatus is fairly large and highly accurate instruments such as flow meters and oxygen sensors (or gas analyzers) are available. 

By the dynamic method, the oxygen concentration was measured as shown in Figure P7.6. The static volume of a fermentation broth, the flow rate of air, and the cell concentration were 11,1.51 min", and 3.0 g-dry cell 1 , respectively. Estimate the oxygen consumption rate of the microbes and the volumetric mass transfer coefficient. 

Fio. 5.82. Oxygen consumption rate of yeast at various oxygen concentrations... 

Figure 5. The metabolism of 3S-S radiolabeled sulfide by boiled and intact isolated Solemya reidi mitochondria. Time zero is prior to addition of mitochondria. When mitochondria are added there is a rapid decrease in sulfide concentration caused partially by dilution of the total volume and partially by binding of sulfide to protein. In the boiled preparation there is very little oxidation of sulfide and no appearance of oxidized products. In the healthy mitochondria the sulfide is rapidly oxidized to thiosulfate. Sulfite and sulfate did not appear as oxidation products. The health of the isolated mitochondria was monitored by oxygen consumption rate in the chamber with succinate as substrate and by the ability to inhibit succinate stimulated respiration with respiratory inhibitors such as cyanide. Error bars represent plus and minus one standard deviation of the mean of three runs.

Parameters that are traditionally used to evaluate the metabolic activity of the cell population inside a hollow-fiber bioreactor include glucose consumption rate (rQLc) and oxygen consumption rate (rcu)- However, these parameters are highly dependent on variations in nutrient feed and metabolic products removal (Gramer et al., 1999). The use of a strategy to overfeed the ICS with nutrients results in a rapid increase in tglc- On the other hand, an increase in product titer and an improved metabolic... 

Jorjani P, Ozturk SS (1999), Effects of cell density and temperature on oxygen consumption rates for different mammalian cell lines, Biotechnol. Bioeng. 64 349-356. 

Fig. 2. Specific oxygen consumption rate (g 02 gX h-1) and biomass accumulation (gdw per culture flask) of A. annua from type a cultures as a function of time. Consumption ( ) biomass (a)...

The oxygen uptake rate terms are considered in more detail. Here they are represented by four terms, oxygen uptake rate due to heterotrophic growth (r ), oxygen consumption rate by organism decay (r ), oxygen uptake rate due to Nitrosomonas (r ) and Nitrobacter (r4) respectively. The specific carbonaceous oxygen uptake rate (SCOUR) is defined by (6)... 

Endothermic homeotherms are characterized by high mass-specific rates of oxygen consumption relative to similar-sized ectotherms. This difference can be shown by examining the allometric scaling relationship between rate of oxygen consumption (M) and body mass (IF). For ectothermic and endothermic animals, whole animal oxygen consumption rate is proportional to total body mass raised to approximately the 0.75 power ... 

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