Microbial Genome Sequencing: Genome Analysis of Galdieria sulphuraria - A Unique Unicellular Thermo-Acidophilic Photosynthetic Microorganism

极端环境中经常居住着极端微生物，它们几乎都是原核生物。然而，红色微藻Galdieria sulphuraria（Cyanidiales）是一种真核生物，在极端的栖息地，如热硫磺泉（pH值0.05至4;温度高达56摄氏度），可以代表高达90%的生物量。这个活化石的基因序列应该可以揭示很多关于现代真核生物进化的信息。Galdieria在50多种不同的碳源上茁壮成长，包括一些稀有的糖和糖醇-这证明了代谢基因的庞大库，几乎没有其他生物可以与之匹敌，并且是生物技术热稳定酶的潜在丰富来源。此外，这种生物耐受有毒金属离子，如镉，汞，铝或镍，这表明在生物修复中的潜在用途。从嗜热菌中分离的蛋白质经常更容易结晶，使得Galdieria蛋白质对结构生物学研究很有价值。最后，高温下Galdieria光合作用是在这个过程的极端范围，因此，这种生物体可能会证明一个有用的模型，对光合机构的物理研究。将对Galdieria sulphuraria的基因组进行测序。将对序列进行整理和注释，提供给公共数据库，并将开发利用这些数据的专门数据库。这项研究将产生丰富的知识，真核生物适应极端环境，蛋白质热稳定性的分子机制，以及在适应极端压力的代谢途径的基因调控的协调。此外，该项目将增加对基因组进化以及植物和质体的生殖发育的理解。

Extreme environments are frequently inhabited by extremophiles, which are almost always prokaryotic organisms. However, the red micro-alga Galdieria sulphuraria (Cyanidiales) is a eukaryote that can represent up to 90% of the biomass in extreme habitats such as hot sulfur springs (pH 0.05 to 4; temperatures up to 56 degrees C). The gene sequences of this living fossil should reveal much about the evolution of modern eukaryotes. Galdieria thrives on more than 50 different carbon sources, including a number of rare sugars and sugar alcohols - evidence of a large repertoire of metabolic genes equaled by few other organisms and a potentially rich source of thermo-stable enzymes for biotechnology. Moreover, this organism tolerates toxic metal ions such as cadmium, mercury, aluminum or nickel, suggesting potential use in bioremediation. Proteins isolated from thermophiles frequently crystallize more readily, making Galdieria proteins valuable for structural biology studies. Finally, the high temperatures under which Galdieria photosynthesizes are at the extreme ranges for this process; thus this organism will likely prove a useful model for physical studies on the photosynthetic apparatus. The genome of Galdieria sulphuraria will be sequenced. Sequences will be collated and annotated, provided to public databases, and specialized databases for the exploitation of this data will be developed. This research will generate a wealth of knowledge on the adaptation of eukaryotic organisms to extreme environments, on molecular mechanisms of protein thermo-stability, and on the coordination of gene regulation in adaptation of metabolic pathways to extreme stress. In addition, the project will add to the understanding of genome evolution, and the phylogeny of plants and plastids.