Shear stress effects on plant cell suspension cultures in a rotating wall vessel bioreactor
ABSTRACT A rotating wall vessel, designed for growth of mammalian cells under microgravity, was used to study shear effects on Taxus cuspidata plant suspension cell cultures. Shear stress, as quantified by defined shear fields of Couette viscometers, improved specific
cell growth rates and was detrimental to volumetric product formation rates.
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ABSTRACT: Oil palm tissue culture offers a potentially practical route to clonal propagation of high yielding palms. However, current tissue culture methods are laborious and costly, and the performance of the cultures can be difficult to describe quantitatively. Computer control of bioreactor processes increases reproducibility and permits quantitative description of the growth of oil palm cultures. Even so, there remain unmet needs in the areas of online metabolite measurement and of automation of the tissue culture process. In this work, we apply Raman spectroscopy for non-destructive off-line quantitation of sucrose, glucose, fructose, nitrate, potassium phosphate and magnesium sulphate metabolites in oil palm bioreactor culture supernatants. We also explore the feasibility of using fluorescence to discriminate between different morphotypes of oil palm calli. Finally, we report the use of flow cytometry to sort oil palm suspension cultures on the basis of size; selected samples were deposited into separate wells in a microplate with one callus particle per well. The technologies described in this article contribute to the development of automated methods for moving and positioning oil palm cells, and for online measurement of metabolites in oil palm bioreactor supernatant.
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ABSTRACT: Salidroside and its aglycone tyrosol are important compounds found in Rhodiola plants. In this study, callus derived from Rhodiola crenulata was induced and grown when explants were incubated on a Murashige and Skoog (MS) medium containing various concentrations of 6-benzyaldenine (BA), naphthalene acetic acid (NAA) and thidiazuron (TDZ). Callus was easily initiated from juvenile leaves in half strength MS medium supplemented with 0.5 mg/L BA and 3.0 mg/L NAA, while full strength MS containing 0.5 mg/L TDZ and 0.5 mg/L NAA was the best for callus subculture and subsequent cell suspension culture. The activities of l-phenylalanine ammonia lyase (PAL) and β-d-glucosidase, two key enzymes in salidroside synthesis, increased at first and subsequently decreased in cell suspension cultures. The salidroside and tyrosol levels in the cell suspension cultures were determined using high-performance liquid chromatography. High levels of salidroside and tyrosol were detected in cell suspension cultures of R. crenulata extracted with 75 % methanol, demonstrating that the biotechnological production of these compounds using plant cell suspension cultures derived from R. crenulata may be an attractive alternative to harvest-based production.Plant Cell Tissue and Organ Culture · 2.61 Impact Factor
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ABSTRACT: Mathematical simulation and experimental measurement of dissolved O2 were performed for extended (up to 8 h) shear testing of Daucus carota (carrot) cell cultures in a conventional Couette viscometer (0.625 mm annulus). The results suggest O2 depletion below critical levels for cell growth may occur. A novel design modification incorporating an O2-permeable silicone-layer spun cast on a porous ceramic bowl was devised. It significantly improved oxygenation of the cell cultures, keeping dissolved O2 near saturation.Biotechnology Letters 01/2001; 23(22):1841-1847. · 1.85 Impact Factor