极端环境微生物.pptx

极端环境微生物;Life in extreme environments Microbes that live in conditions that would kill other creatures. Microbes that Love of extremes 对其它生物是极端或致死环境;生活在极端自然环境中微生物是生命奇迹，它们蕴涵着生命进化历程丰富信息，代表着生命对于环境极限适应能力，是生物遗传和功效多样性最为丰富宝藏。;极端酶（extremozymes）;极端环境微生物 thermophiles psychrophiles acidophiles alkophiles halophiles barophiles Microorganisms resistant to radiation;1. High temperature environments and Thermophiles 1.1 background Hot springs (陆地热泉) Shallow submarine hydrothermal systems (浅海底热泉) abyssal hot vents (深海火山口) ;Thomas D. Brock Brock Biology of Microorganisms Yellowstone National Park 82°C 热泉发觉了细菌 水生栖热菌 (Thermus aquaticus) 崭新世界、新研究领域;在热泉处（白色）因为温度高，没有光合细菌，伴随温度降低，开始出现光合细菌，颜色变深;old faithful erupts(忠诚喷泉) ，每次能把7500~1.2万加仑泉水喷向高空，水柱高达55米！滚烫热水遇冷气后又在空中凝结成白色云柱，壮观中还透出一些妩媚; ; 1.2 嗜热菌(Thermophiles)主要类群 To date, over 50 thermophiles are known. The most extreme is Pyrolobus fumarii, which can multiply in temperatures up to 113°C. optimal temperature: 60~62C: Procaryote 70~73C: photosynthetic bacteria over 100C : a few unusually heat-adapted Archaea called hyperthermophiles.;;Temperatures approaching 100 °C normally denature proteins and nucleic acids, and increase the fluidity of membranes to lethal levels. Chlorophyll degrades above 75°C, excluding photosynthesis; 1.3 适应高温分子适应性 How can hyperthermophiles maintain the integrity of their macromolecules at temperatures where the chemical degradation of DNA and proteins is greatly accelerated ? 细胞膜中膜脂高饱和度脂肪酸 蛋白质热稳定性 遗传物质稳定性;2. Low temperature and cold adapted microorganisms The Majority of the Earth’s ecosystems are Cold Environments, 90 percent of the worlds oceans are “cold” Cold polar seas and soils, Glaciers, deep-sea areas High mountains covered with snow Ice and brine pools from polar regions, High altitude snow fields and other high altitude habitats, Caves, Refrigerators, Upper atmosphere;Cold environments;Most