MoMiX - Modelling Mixotrophy in the extremophile alga Galdieria sulphuraria

Galdieria sulphuraria是一种世界性的光合微生物，孤立于火山地带。这种嗜酸性和嗜热菌的特征在于高代谢灵活性以及高生物质生产率。硫磺菌能够在光养状态（仅使用光作为能量来源）、异养（发酵或减少碳呼吸）以及兼养条件（同时使用光和减少碳）下生长。G. sulphuraria被认为是生物技术应用的新兴系统。另一方面，这些独特性能的分子基础在很大程度上仍然未知。出于这个原因，我们提出了一个项目，以了解Galdieria mixotrophic增长的分子机制，实现生物技术应用的最大生物量的一步。这将通过在光/兼养条件下对不同菌株进行高通量筛选（光合作用、生长）来实现。比较基因组学、蛋白质组学以及代谢分析技术的发展，将使G.这要归功于一种新的生物信息学工具，该工具旨在对代谢网络进行详细的重建和可视化以及系统范围的分析。这将使得有可能进行代谢建模以及通量平衡分析，从而确定光和碳源转化的制约因素和限制步骤。为了实现这些目标，我们组建了一个由三个合作伙伴（LPCV，HHU，BGE）组成的财团，他们在光合生物的代谢研究方面有着坚实的记录，他们都是各自科学领域的研究领导者。合作实验室为G.硫藻（HHU）的基因组序列测定，以及微藻兼养机制（LPCV）的鉴定。三个合作伙伴将利用互补的方法学专业知识（LPCV：生理学、呼吸和代谢重建; BGE：蛋白质组学、生物信息学; HHU：比较基因组学和代谢通量）研究兼养代谢的关键步骤。该项目将提供有关如何优化的知识这种藻类的生产力，并将从未来代谢工程的角度确定提高生物质生产力的目标。

Galdieria sulphuraria is a cosmopolitan photosynthetic microalga isolated in volcanic zones. This acidophilic and thermophilic alga is characterized by a high metabolic flexibility as well as by a high biomass productivity. G sulphuraria is able to grow in phototrophic regime (exclusive use of light as a source of energy), heterotrophy (fermentation or reduced carbon respiration) as well as in mixotrophic conditions (simultaneous use of light and reduced carbon). G. sulphuraria is considered as an emerging system for Biotech applications. On the other hand, the molecular bases of these unique performances are still largely unknown. For this reason, we propose a project to understand the molecular mechanisms of Galdieria mixotrophic growth as a step towards achieving maximum biomass for biotechnological applications. This will be achieved by high-throughput screening (photosynthesis, growth) of different strains under photo / mixotrophic conditions. Comparative genomics, proteomics as well as metabolic analyses will make it possible to reconstruct in silico the metabolism of G. sulphuraria, thanks to a new bioinformatic tool designed for detailed reconstruction and visualization and system-wide analyses of metabolic networks. This will make it possible to carry out metabolic modelling as well as flux balance analysis, and thus to identify the constraints and the limiting steps in the conversion of light and carbon sources. To achieve these goals, we have assembled a consortium of three partners (LPCV, HHU, BGE) with a solid record in the study of the metabolism of photosynthetic organisms, all leaders of research in their scientific fields. The partner laboratories contributed to the first studies of G. sulphuraria (HHU), including the sequencing of its genome, and the identification of the mechanism of mixotrophy in microalgae (LPCV). The three partners will study the key steps of mixotrophic metabolism with complementary methodological expertise (LPCV: physiology, respiration and metabolic reconstruction; BGE: proteomics, bioinformatics; HHU: comparative genomics and metabolic fluxes).This project will provide knowledge on how to optimize the productivity of this alga and will identify targets for improved biomass productivity from the perspective of future metabolic engineering.