LEDitGROW - Beleuchtungssysteme zur Optimierung von Pflanzenzellkulturen für die Sekundärmetabolit-Produktion

• LEDitGROW - Lighting systems to optimize plant cell cultures for secondary metabolite production

Beuel, Ann-Katrin; Commandeur, Ulrich Heinrich (Thesis advisor); Schillberg, Stefan (Thesis advisor)

Aachen : RWTH Aachen University (2022)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen University, 2022

Abstract

Plant secondary metabolites, which are used for example in cosmetic products, but also as food additives, can be produced in plant cell cultures (PCCs). In the context of this thesis two lighting systems for PCCs were developed in order to increase the secondary metabolite yield in PCCs by using light of specific wavelengths: LEDitREST (LiR) for callus cultures and LEDitSHAKE 2.0 (LiS 2.0) for suspension cultures. Both systems allow individual control of the light spectrum, intensity and duration of the illumination. With LiR 24 different light conditions can be used in parallel, while LiS 2.0 allows 12 different light conditions to be used in just one shaker incubator. To determine whether a possible influence of light of specific wave lengths on PCCs can be reliably investigated with LiR and LiS 2.0, four questions were formulated and answered using statistical experimental design on the example of different PCCs: Does light have an effect on a) the biomass formation during the establishment of a suspension culture; b) the biomass formation of an established suspension culture; c) the secondary metabolism of a suspension culture; d) the overall process development of a PCC? Using the lighting systems accelerated biomass formation during the establishment of a serviceberry suspension culture (doubling of biomass formation under optimized light condition compared to standard condition). In addition, biomass formation of tobacco BY2 cells (traditionally cultured in the dark) was significantly increased when cultivated under red light: after one week of cultivation, the optimally illuminated cultures formed almost 1.4 times more biomass than the cells cultivated in darkness. Furthermore, anthocyanin content in grape suspension cultures was increased by up to 130% (cyanidin glucoside) by using the optimal light conditions compared to the standard cultivation condition. As part of the thesis, additionally fenugreek cell cultures were newly established in LiR and LiS 2.0, and the 4-HIL content of these cultures was positively affected by light: three cultures were established that featured a 50-130% higher 4-HIL productivity than cultures generated using the conventional method (establishment of cultures either with only white light in a light rack/shaker or cultivation in darkness). In these cases, an increase in biomass formation as well as secondary metabolite content was achieved by adjusting the light conditions without using alternative strategies such as elicitation or genetic modification. This is a major advantage, as the use of genetically modified ingredients is undesirable, especially in the food and cosmetic sectors. The influence of light on PCCs, especially on suspension cultures, could thus be confirmed by using the lighting systems developed in this thesis.

Institutions

• Department of Biology [160000]
• Chair of Molecular Biotechnology [162910]