Plant suspension culture

A considerable amount of extracellular polysaccharides is produced in the process of cultivation of certain plant suspension cultures and the spent culture medium has proved to be an accessible source for their production (1-3). The interest in investigating these extracellular polysaccharides has been quite strong over the past 10-15 years, motivated by their biological activity (4,5). Plants of the Asteraceae family, as well as their cell cultures, have been established to contain polysaccharides with immunostimulating activity (1-6). The object of our research was Helianthus annuus 1805 cell culture (Asteraceae), which according to the preliminary investigation produces a considerable amount of exopolysaccharides. 

Increasing concentrations of PVP 360,000 up to 1.0 g L 1 improved antibody accumulation in hairy root culture medium however, above this concentration there was no further increase in antibody levels [19]. Addition of PVP after extracellular foreign protein levels had decreased during plant suspension culture did not result in a recovery of the protein [66]. 

Tab. 7.2 Pharmaceutical proteins produced in plant suspension cultures... 

DC 196 Kleinig, H., and C. Kopp. Lipids, lipid DC208 turnover, and phospholipase D in plant suspension culture cells (Daucus carota). Planta 1978 139(1) 61-65. 

De Armond, R., Bohnert, H.J. Thomas, J.C. (1991). Growth, amino acid composition, and PEPCase in ice plant suspension cultures. Plant Physiology 96S, 96. 

For initial studies, plant cell suspensions are typically cultivated in shake flasks agitated by a gyratory shaker, but for the economical production of commercial products, plant suspension cultures must be cultivated in larger bioreactors. 

What can be done to achieve this necessary improvement Most plant cell products are secondary metabolites, which means that plant suspension culture systems involve a growth phase and a production phase. In any commercial system, one will probably want to separate physically these two phases. Unfortunately, one has to add a growth hormone such as 2-4-D for a successful growth phase, and these hormones must be completely removed before elicitors are added to the production phase to induce the secondary product. Optimizing this two-stage system is an engineering challenge. 

The greatest amount of work on scale-up of bioprocesses relevant to plants has been with cell suspension cultures. The potential for chemicals production and for biomass generation, from large scale plant suspension cultures has indeed been recognized for some time (8-10). Many factors remain to be resolved, however, as evidenced by the fact that only one process during the past 25 years has reached commercialization (5). Some of the barriers to successful commercialization are associated with ... 

LaCount W, An GH, Lee JM (1997) The effect of polyvinylpyrrolidone (PVP) on the heavy chain monoclonal antibody production from plant suspension cultures. Biotechnol Lett 19 93-96. 

Lee JH, Kim NS, Kwon TH, Jang YS, Yang MS (2002) Increased production of human granulocyte-macrophage colony stimulating factor (hGM-CSF) by the addition of stabilizing polymer in plant suspension cultures. 

Funk C, Giigler K, Brodelius PE. Increased secondary product formation in plant suspension cultures after treatment with a yeast carbohydrate preparation (elicitor). Phytochemistry 1987 26 401-5. 

Among the many reports about PAL being located at different membranes, partly as con onent of a channelling mlcroccmpartment, I would like to mention the PAL of plant suspension cultures, which could. In part, be attributed also to membranes. Careful analysis demonstrated that these membranes are vesicles of the endoplasmic reticulum (5). 

The continuous production of secondary metabolites was designed based on plant suspension culture with suitable bioreactor by the use of Eschscholzia californica. The secondary metabolite cells were elicited with chitin at fourth day in liquid culture media, these free secondary metabolite cells were debris and continuously pumped into the extraction columns containing fluidized XAD-7 resins. The production level was similar to the culture without resins with a maximum of 2.06pmole/g DW total alkaloids, with 1.54pmole/g DW of resins by perfusion cultures. However, the nutritional status was identified by elicitation as a major cause and reduced the production (Dobbeleer et al. 2006). 

Hydroxybenzoic Acid Turnover.—Hydroxybenzoic acids accumulate, mainly in bound form, in most higher plant tissues and they are undoubtedly subject to active turnover. Their fate, however, has hardly been studied. Recent experiments by Harms et al. using plant suspension cultures suggest that... 

---