Surface-associated plant cell culture

Biofilms are typically characterized as a consortium of microorganisms, which adhere to each other and often to surfaces. This adhesion is realized by extracellular polymeric substances (EPS), which are secreted by the microorganisms and mainly consist of water, polysaccharides, proteins and lipids as well as nucleic acids and lysis products [1]. Although cultured plant cells are not typically considered biofilms, parallels can be found in the properties of plant calli. These callus cells tend to form cohesive aggregates, owing to their extracellular matrix, and often strongly adhere to the agar plates they are kept on. The extracellular matrix of plant cells is mainly composed of structural polysaccharides, such as xyloglucans, arabinogalactans [2], homogalacturonan and extensins [3] among others. Cultured plant cells were found to adhere to surfaces before [4]. Surface-associated plant cell culture may have potential in a (semi‑)continuous cultivation including product secretion, as was shown in principle for alginate-embedded plant cells [5]. For cyanobacterial biofilms, an efficient strategy for EPS extraction was recently developed [6]. The transferability of these protocols to biofilm-like growing plant calli of Ocimum basilicum is currently being investigated. Subsequently, the composition of the extracellular matrix extracted from cultured O. basilicum cells is of interest. Furthermore, the adhesive properties of O. basilicum suspension cultures to microstructured surfaces and the potential role of the extracellular matrix are under investigation. An investigation of culture properties in an aerosol photobioreactor [7] is planned as well.

This project is financially supported by the German research foundation (DFG, project number SFB 926-C03).

 

References:

[1]      H. C. Flemming, T. R. Neu, and D. J. Wozniak, “The EPS matrix: The ‘House of Biofilm Cells,’” J. Bacteriol., vol. 189, no. 22, pp. 7945–7947, 2007.

[2]      I. M. Sims, K. Middleton, A. G. Lane, A. J. Cairns, and A. Bacic, “Characterisation of extracellular polysaccharides from suspension cultures of members of the Poaceae,” Planta, vol. 210, no. 2, pp. 261–268, Jan. 2000.

[3]      M. Popielarska-Konieczna, K. Sala, M. Abdullah, M. Tuleja, and E. Kurczyńska, “Extracellular matrix and wall composition are diverse in the organogenic and non-organogenic calli of Actinidia arguta,” Plant Cell Rep., no. 0123456789, 2020.

[4]      R. J. Robins, D. O. Hall, D. ‐J Shi, R. J. Turner, and M. J. C. Rhodes, “Mucilage acts to adhere cyanobacteria and cultured plant cells to biological and inert surfaces,” FEMS Microbiol. Lett., vol. 34, no. 2, pp. 155–160, 1986.

[5]      Y. Kobayashi, H. Fukui, and M. Tabata, “Berberine production by batch and semi-continuous cultures of immobilized Thalictrum cells in an improved bioreactor,” Plant Cell Rep., vol. 7, no. 4, pp. 249–252, 1988.

[6]      D. Strieth, J. Stiefelmaier, B. Wrabl et al., “A new strategy for a combined isolation of EPS and pigments from cyanobacteria,” J. Appl. Phycol., no. Fromme 2008, Feb. 2020.

[7]        S. Kuhne, D. Strieth, M. Lakatos, K. Muffler, and R. Ulber, “A new photobioreactor concept enabling the production of desiccation induced biotechnological products using terrestrial cyanobacteria,” J. Biotechnol., vol. 192, no. Part A, pp. 28–33, 2014.