This workshop session will be organized in four main topics. Each participant will choose a workshop session. The objective is to establish a debate and a discussion moderated by the different participants of the workshop by exchanging their experience and their approach in the different thematics. In order to construct the session, a 2-slides PPT presentation is requested in order to determine the main topics developed during the session.
The day will end with a join session and a presentation of the main results and questions addressed in each workshop session.
Experimental Modelling in Laboratory: how far can we go ?
Two major approaches for characterizing mineral formation during the activity of microorganisms. The first is the study of naturally-occurring organominerals and the combined environmental parameters associated with the biomineralizing environment. The main difficulty of this approach is the deconvolution and interpretation of complex interconnected processes that vary in time and space (e.g., with pronounced 3-D chemical and physical gradients). The second approach, “experimental modeling”, relies on laboratory studies conducted under controlled chemical, physical and biological conditions, often with pure cultures. These studies are typically carried out under unnatural conditions lacking multiple microbial species with diverse metabolisms interacting simultaneously. Such a natural complexity is hard to reproduce in laboratory, mainly due to the difficulty of mimicking physicochemical gradients and/or creating the microniches where mineral precipitations occur under local (µm-scale) supersaturation. However, the experimental approach may reveal the potential role of individual metabolisms on mineral formation. In addition, controlled laboratory experiments permit screening of a wide range of environmental conditions. Ultimately this aids in (i) assessing various extreme scenarios of microbial organomineralization and (ii) better quantifying the role of each individual factor controlling mineral precipitation. In this workshop topic, we will discuss and generalize the different aspects of laboratory modeling of microbial precipitation in the order to optimize and develop this approach.
Biomineralization vs. organomineralization and the role of intrinsic and extrinsic factors in shaping the microbialite systems
Microbialite fabrics from formation to diagenesis and preservation (or lack thereof) in the fossil record
Into deep time: looking for microbialite biosignatures in the fossil record