Glucose consumption rate

Optimal conditions for insect cell growth have been extensively studied, but for product expression with a baculovirus infected insect cell the focus should be on the difference in the metabolic requirements of infected vs. uninfected cells, which has been observed to differ after infection. The alanine specific production rate decreases almost four-fold, while phenylalanine specific consumption rate increase 11-fold and glutamine specific consumption decrease [65]. Both an increase [66] and a decrease [67] in glucose consumption rates of insect cells after infection have been reported. This reflects some differences in the media and vectors that were used however, it is normal to expect a higher metabolic burden after infection due to the increase in protein expression rates caused by the infection. This creates a concern about the impact of nutrient limitations on the productivity of the system. 

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... 

The central parameter in cell culture is the viable cell concentration. The specific growth rate ( x), the specific death rate k and the fraction of viable cells (/ ) are used to characterize the proliferative state and health of a culture. These parameters are calculated from the viable and non-viable cell concentrations using equations appropriate for the type of culture vessel employed (see below). The viable cell concentration is also used to calculate the metabohc quotients (e.g. specific glucose consumption rate), as discussed in a later section. In the absence of cell concentration data, analysis is limited to ratios of metabolic rates (see below). 

Figure 42.7 Metabolic quotients for the glucose step change experiment described in Figure 4.2.5. (a) Specific glucose consumption rate (mmol glucose consumed viable celL da>r ) as a function of culture time, (b) Specific lactate production rate (mmol lactate produced viable celH day" ) as a function of culture time. Adapted from Miller et al (1989) by permission of Biotechnology and Bioengineering.

For most cell lines it has been found to increase linearly with the specific growth rate. Thus the specific rate of glucose uptake is often expressed as a function of x by Equation 4.3.3, which contains two parameters the non-growth-assodated specific glucose consumption rate, rriQ c (mmol glucose 1(T cells h ), and the... 

Specific glucose consumption rate (mmol 10 cells h" )... 

Batch, repeated batch feed and harvest modes Glucose consumption rate (GCR) ... 

Figure 5.9.4 Glucose consumption rate ( ) and lactate production rate (A) in batch mode.

As the main purpose of this paper is to implement an adaptive control strategy for controlling the SSFSE process by means of starch feeding only when the glucose consumption rate is higher than its production rate it is necessary to follow these two rates on line. Unfortunately, such kind of sensors are not available and therefore, soft... 

By observing equation (2), it can be seen that glucose consumption rate 02 is given by ... 

Because of higher ATP productivity, glucose consumption rate will be slow. 

The maximal activities of the individual glycolytic enzymes of the bloodstream form of T. brucei are all in large excess of the overall glucose consumption rate of 85 nmol min (mg protein) It is not possible to identify the rate-limiting step in... 

Chang are characteristic of the literature phenomena examined [G = glucose, A = oxygen, B = H2O2, and P = oxidized glucose] Glucose consumption rate (by oxidase (ox)) ... 

MV mean value SD standard deviation Gr.A group A [pm-e silicone oil and poly(propylene glycol) PPG and silicone oil/PPG mixture] Gr.B group B (aqueous emulsion with only 10% S184) X cell mass concentration Yx/s yield coefficient of growth with respect to substrate P productivity of P-galactosidase SP specific productivity SG specific glucose consumption rate [51]... 

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