Suspended Cell Cultures

While most appfications were performed in suspended cell cultures some authors showed that the application of NADH-dependent fluorescence monitoring is also possible in immobifized cell systems. Here the growth of Clostridium acetobutylicum and the Saccharomyces cerevisiae immobilized in different calcium alginate structures was studied. However, calibration of the culture fluorescence signal with the biomass concentration was not possible but qualitatively an increasing biomass also led to an increase in the fluorescence signals. 

Sato K, Nakayama M, Shigeta J (1996) Culturing conditions affecting the production of anthocyanin in suspended cell cultures of strawberry. Plant Sci 113 91-98. 

Because there is no physiological change of the microbes when immobilized onto the activated carbon particles, the kinetic expression of the cell growth obtained from a suspended cell culture can be applied equally well to the immobilized system. The bacterial growth kinetics for free and captured cells is... 

Also, the kinetic expression of cell death obtained from a suspended cell culture is applied equally to the immobilized system. Sen et al. [142] proposed an irreversible first-order reaction for death of bacterial cells ... 

The perceived sensitivity of plant cells to the hydrodynamic stress associated with aeration and agitation conditions is typically attributed to the physical characteristics of the suspended cells, namely their size, the presence of a cell wall, the existence of a large vacuole, and their tendency to aggregate. Table 1 illustrates some of the differences between plant cells and other biological systems. Chalmers [19] attributed shear sensitivity in mammalian cultures at least in part to the fact that these cells occur naturally as part of a tissue, surrounded by other cells. The same is true for plant cells. The more robust microbial systems, on the other hand, exist in nature as single organisms or mycelial structures, very close to the forms they assume in submerged culture. 

The addition of PVP 360,000 at a concentration of 0.75 g L 1 has been reported to yield a 35-fold increase in the level of extracellular foreign protein in suspended plant cell cultures [66]. The effectiveness of PVP in stabilizing secreted proteins depends on both the polymer molecular weight and its concentration. Low-molecular-weight (10,000 and 40,000) PVP was found to be less effective than PVP 360,000... 

In recent years, extensive attention has been focused on finding cultured plant cells that can be used as catalysts for organic functional group transformations. A number of transformations employing freely suspended or immobilized plant cell cultures have been reported.24 For example, Akakabe et al.25 report that immobilized cells of Daucus carota from carrot can be used to reduce prochiral carbonyl substrates such as keto esters, aromatic ketones, and heterocyclic ketones to the corresponding secondary alcohols in ( -configuration with enantiomeric excess of 52-99% and chemical yields of 30 63%). 

Plant. Hiickelhoven et al. (1997) studied the metabolism of pyrene by suspended plant cell cultures of soybean, wheat, jimsonweed, and purple foxglove. Soluble metabolites were only detected in foxglove and wheat. Approximately 90% of pyrene was transformed in wheat. In foxglove, 1-hydroxypyrene methyl ether was identified as the main metabolite but in wheat, the metabolites were identified as conjugates of 1-hydroxypyrene. 

Fluorescence Labeling of Surface Antigens of Attached or Suspended Tissue-Culture Cells... 

A scale-up of the dialysis reactor system for suspended cells is feasible by application of external dialysis modules, which are coupled between a culture vessel and a dialysis vessel (Fig. 3). The culture broth and dialysis medium are pumped in an external loop through the dialysis module. 

Cell Retention Devices for Suspended-Cell Perfusion Cultures... 

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