Master University Rennes 1, Rennes, France
Fundamental and applied Microbiology
Paleontology, PaleoEnvironment and Prehistory
Thank you for stopping by my academic science website. I am a curious scientist and am always inquiring about the world that surrounds me. I am especially interested in the origin of life and how to understand and interpret the fossil record in ancient rocks. My primary interest is on fossil bacteria trapped in ancient amber but am also focused on the interaction between bacteria and minerals during experimental fossilization of bacteria. I am eager to learn more and share this knowledge with interested people. Take a look around and explore my academic work and ongoing projects. Feel free to get in touch if you have any questions or would like to learn more
2016-2018. University of Rennes 1, Bretagne, France.
Master’s 2 degree in Paleontology, Palaeoenvironment, Prehistory
Fossilization, Evolution, Dating, stratigraphy, Paleoenvironment, Paleoclimat and Paleoecology. SEM, field excursion.
2014-2016. University of Rennes 1, Bretagne, France.
Master’s 1 and 2 degree in Fundamental and
Bacterial genetics and genomics, Molecular biology, bacterial interactions, host-bacteria
relationships, Microbial ecology, Food microbiology and safety, methods of bacterial identification.
2011-2013. University of Kasdi Marbah, Ouargla, Algeria.
Master’s 1 and 2 degree in Applied Microbiology.
2008-2011. University of Kasdi MARBAH, Ouargla, Algeria.
Bachelor’s degree in Applied Microbiology
Microbial genetics, food microbiology, Environmental microbiology, Separation and isolation methods of bacteria.
2008. High school diploma, Ouargla, Algeria.
INTERNSHIPS AND PUBLICATIONS
How microfossils analogous to those of the ancient rock record form (silicified stromatolites), an experimental study
In this ongoing project we are trying to understand how stromatolites form. We are investigating the potential for an upward migration of cyanobacteria due to phototaxis, in order to keep pace with the deposition of amorphous silica. Using endolithic cyanobacterial strains and amorphous silica gels or quartz layers we examine the potential for the attenuation of UV-A and visible light. We hypothesize that the distance the cyanobacteria migrate will be a function of silica thicknesses and could be informative for processes in modern hot springs, where cyanobacteria and amorphous silica form distinct layers as a response to changing environmental conditions and seasons. Cyanobacteria need sufficient visible light for photosynthesis but protection from harmful UV radiation, especially on the early earth, in order to thrive. In this project we want to demonstrate process experimentally in order to better understand the alterations of amorphous silica and bacteria in seasonal hot spring layers, but also the applicability for deep time. In a study by Konhauser et al. (2001) Calothrix sp. were observed to move upward as amorphous silica deposition continues, but the cyanobacteria, while abundant did not reach the surface. The cyanobacteria were always observed to be below a few millimeters of silica, suggesting that the amorphous silica plays a role in shielding cyanobacteria from UV radiation or optimising levels of visible light.
Fossil bacteria from messinian Gypsum from Algeria
Internship in Università degli Studi di Modena e Reggio Emilia and Università degli Studi diParma, Modena and Parma city, Italy.
The study of microfossils record preserved in Miocene gypsum is an important way to study the Messinian Salinity Crisis, an extreme event that affected the Mediterranean Sea from 5.971 to 5.33 Ma. The Mediterranean became a giant salina and most life forms were wiped out. The study of the surviving life forms included into gypsum crystals may help us to understand, not only what happen in the Messinian, but also to understand the complex mechanisms involved in Earth's responses to extreme environmental changes at different temporal and spatial scales. In this study, the stratigraphy and the microfossil record of three localities (Boutlelis, Ammandier and Quarry Sidi Boutbal) in the Messinian (Miocene) gypsum of the Murdjadjo basin from North-West of Algeria were investigated. We used optical and Scanning Electronic Microscopy associated with X-EDS for
microbial fossils investigation, coupled with strontium isotopes analyses. The results showed that the gypsum belongs to the first phase of the salinity crisis (Primary Lower Gypsum) as the Sr isotopes analyses obtained show respectively a values of 0,708955, 0,708965 and 0,708984. The crystal show a very rich record of microfossils that differ in abundance and diversity in the 3 outcrops with an observation of rod shape filaments, diatoms and zooplankton-like fossils. Dolomite precipitation as sub-spherical porous structures were observed inside filaments in the Sidi Boutbal gypsum. The gypsum deposit probably formed a very rich hypersaline lagoon at dry season, both photosynthetic bacteria and sulfate reducing bacteria could be implicated in dolomite formation by modifying the micro-environment around the filament cells using the cyanobacterial organic compounds. This is the first contribution describing the microbial fossils from the Algerian Messinian gypsum.
UMR 5554, Institut des Sciences de l’Evolution - Montpellier
Institut de Botanique, 163 rue Auguste Broussonnet
In an ecosystem, many interactions between organisms exist, such as bacteria, fungus, plants and vertebrates . However, few remains of these organisms are fossilized, making difficult to understand the paleoecosystems. The Amber (fossilized resin) allows an excellent preservation of organisms. Observations under a microscope of the santonian amber from Piolenc (Franc) have allowed the discovery of several microorganisms filamentous and some protists. These fossils have been described and their modality of preservation (actual colonization or trapping) has been defined. RAMAN analyzes have improved understand this fossil assemblage. At the end all these data show that the Paleoecosystem of Piolenc was a relatively dry environment, but some water sources (fresh or marine) are not excluded.
Fossil bacteria Preserved in Cenomanian Amber from Cadeuil and Fouras, France
The microorganisms of amber are a valuable source of information to help better understand ancient ecosystems. Amber is one of the few fossil allows to study paleoenvironments in detail. The Cenomanian amber of Cadeuil and Fouras has
microorganisms, particularly filamentous organisms represented by Actinomycetes or Fungi. These inclusions have morphologies similar to micro-inclusions of other Cretaceous French amber. Within the forest Palaeoecosystem of Cadeuil and Fouras, the filamentous microorganisms were able to grow and / or use tree resin. However, it has not observed a form of trapping of microorganisms. The observed microorganisms explain, by their situation and direction of growth in the amber, that the secretion of the resin was rather in a humid environment that allows the body such as actinomycetes and fungi to easily grow in the resin before solidification. The Cenomanian is known to being a period where the temperature was high which suppose the trees that secreted the resin were close to a water source that would allow with the heat to release a moisture favorable to the growth of this type of microorganisms. So we still do not know the modes of growth of bacteria and fungi in the resin and if these organisms use certain resin substances for metabolism. Studying the microorganisms of amber remains dependent unfortunately so far on morphological identifications. Organic molecules such as DNA still little known and could be a research focus to better understand these microorganisms and all that remains to be studied deeply.
Ability of oil contaminated soil bacteria to produce biosurfactant
The objective of our study is to evaluate the emulsifying activity of telluric bacterial strains isolated from different soil samples polluted by hydrocarbons. Despite harsh environmental conditions, 17 bacterial strains were isolated. The cultivation of these strains in a medium having as sole source of carbon and energy crude oil (2%) allowed us to confirm their ability to grow in the presence of hydrocarbons.The emulsification test applied to the bacteria studied in the presence of oil, gas oil or sunflower oil as an emulsification substrate, allowed us to select four strains (S1, S2, S8 and S9) whose best respective emulsions are 42.17%, 57.8%, 54.58% and 28.63%.These promising results highlighting the high emulsifying power of the strains studied can be exploited in the process of bioremediation of soils polluted by hydrocarbons.