Research Interest

Project 1: Stress impact on plant physiology

Despite the contamination of water, soil and the food chain by heavy metals (HM), very little research is devoted to this problem in Tunisia. To our knowledge, very few research structures are interested in the effects of HM on both plants and animals. Since 1993, our research team has set itself to study the effects of HM on several aspects of the growth and development of some plants grown on hydroponic medium. Physiological, biochemical and molecular aspects are studied on all developmental stages of a plant (germination, seedlings, and fully-grown plants) in collaboration with labs in Tunisia and worldwide. This led to the publication of scientific articles and the defense of a wide range of doctoral and master theses.

On another side, phytoremediation (the depollution of contaminated plants using accumulating plants) constitutes a very promising mean for the revaluation of these soils. Indeed, the scientific community and public authorities are beginning to accept the importance of the approach using certain non-harmful chemical inputs to "neutralize" or at least reduce the harmful effects of HMs, example; chelators and ion competitors (EDTA, EGTA, Citrate, Oxalate, Malate, Mg, Ca, ...), phytohormones, melatonin, and their derivatives, NO and H₂S molecules. Our team is specialized in redox status in plant root and leaf cells and interested also in the biochemical and molecular levels. Moreover, we target photosynthesis, gas exchange, and chlorophyll fluorescence as a non-invasive tool to study the photochemistry of PSII and the photosynthetic machinery in-vivo.

Team members

 Project 2: Molecular microbial ecology

The interest focused on the diversity of microorganisms present in the anaerobic digesters of wastewater-treated plants. In collaboration with Genoscope-CEA (France), methanogenic Archaea and their interactions within different sampled digesters were analyzed using molecular tools (Guermazi et al. 2018). In Tunisia, as in the rest of the world, the quantities of sludge generated following the depollution of urban wastewater are increasingly important and pose an environmental problem since they are often landfilled for lack of incineration, which is too costly in terms of energy, or agricultural spreading because of their toxicity. However, the depollution potential of this sludge is still possible to make. We highlighted a microbial diversity of digested sludge treated with gamma rays in order to characterize the microorganisms resistant to gamma irradiation. Then, the work targeted the various contaminants of wastewater. Our team is now interested in working on the impact of hospital effluents on soil microorganisms raising the importance of the metal toxicity of these effluents and the consequences on the growth and activity of telluric microorganisms receiving these effluents. More recently, a study on the soils of the plots of Cebalat Borj Touil irrigated with wastewater has made it possible to emphasize a relationship between the duration of irrigation of these lands with the increase of bacterial resistance to antibiotics and metals. We also target the impacts of treated wastewater on the properties of irrigated soils using high-throughput qualitative and quantitative molecular tools. One of the goals sought in the characterization of microorganisms tolerant to different wastewater pollutants and their use as a biotechnological tool in the remediation of polluted soils.

Team members

Project 3: Phytochemistry and biological activities of native medicinal species in Tunisia

Tunisia is an important reserve of spontaneous aromatic and medicinal plants, but the exploitation of these resources remains poorly studied for species such as Mercurialis annua L. and other woody plants. Thus, a better valorization of these species is essential. Our team is mainly interested in the phytochemical screening of extracts from different parts of the plant with the aim of identifying biomolecules potentially responsible for biological activities for a better exploitation on the applied level.

Team members