인간의 삶과 역사 속의 미생물

1. 인간의 삶과 역사 속의 미생물 강의자료ppt-11 2011-2학기

2. 미생물은어떤 존재인가?

3. 물질순환과 미생물- 모든 생물의 생사를 좌우하는 미생물 -

4. 탄소순환

5. The Carbon Cycle • Carbon is cycled through all of Earth’s major carbon reservoirs • i.e., atmosphere, land, oceans, sediments, rocks, and biomass

7. Major carbon reservoirs on Earth

8. CO2 in the atmosphere is the most rapidly transferred carbon reservoir • CO2 is fixed primarily by photosynthetic land plants and marine microbes • CO2 is returned to the atmosphere by respiration of animals and chemoorganotrophic microbes as well as anthropogenic activities • Microbial decomposition is the largest source of CO2 released to the atmosphere

9. The carbon and oxygen cycles are intimately linked • Phototrophic organisms are the foundation of the carbon cycle • Oxygenic phototrophic organisms can be divided into two groups: plants and microorganisms - Plants dominant phototrophic organisms of terrestrial environments - Phototrophic microbes dominate aquatic environments

11. 질소순환

12. The Nitrogen Cycle • Nitrogen • A key constituent of cells • N2 is the most stable form of nitrogen and is a major reservoir • The ability to use N2as a cellular nitrogen source (nitrogen fixation) is limited to only a few bacteria

14. 유황순환

15. The SulfurCycle • Sulfur transformations by microbes are complex • The bulk of sulfur on Earth is in sediments and rocks • The oceans represent the most significant reservoir of sulfur in the biosphere

16. Hydrogen sulfide is a major volatile sulfur gas that is produced by bacteria via sulfate reduction or emitted from geochemical sources • Sulfide is toxic to many plants and animals and reacts with numerous metals • Sulfur-oxidizing chemolithotrophs can oxidize sulfide and elemental sulfur at oxic/anoxic interfaces

17. Organic sulfur compounds can also be metabolized by microbes • The most abundant organic sulfur compound in nature is dimethyl sulfide (DMS) • Produced primarily in marine environments as a degradation product of dimethylsulfoniopropionate (an algal osmolyte) • DMS can be transformed via a number of microbial processes

19. 철순환

20. The IronCycle • Iron is one of the most abundant elements in the Earth’s crust • On the Earth’s surface, iron exists naturally in two oxidation states • Ferrous (Fe2+) • Ferric (Fe3+)

22. Fe3+ can be used by some microbes as electron acceptors in anaerobic respiration • In aerobic acidic pH environments, acidophilic chemolithotrophs can oxidize Fe2+ (e.g., Acidithiobacillus)

23. A Microbial Mat Containing High Levels of Ferrous Iron (Fe2+)

24. Pyrite (황철광, FeS2) • One of the most common forms of iron in nature • Its oxidation by bacteria can result in acidic conditions in coal-mining operations

25. Pyrite and Coal

26. Acid mine drainage • An environmental problem in coal-mining regions • Occurs when acidic mine waters are mixed with natural waters in rivers and lakes • Bacterial oxidation of sulfide minerals (e.g. pyrite) is a major factor in its formation

27. Ferroplasmaacidarmanus Streamers of F. acidarmanus, an extremely acidophilic iron-oxidizing archaeon

28. 인순환

29. The Phosphorous Cycle • Has no gaseous component • Environmental phosphorus usually present in low concentrations; is often the growth limiting nutrient • Phosphorus exists in both organic and inorganic forms

31. 망간순환

32. The Manganese Cycle • Involves the transformation of manganous ion (Mn2+) to MnO2 • occurs in hydrothermal vents, bogs and is an important part of rock varnishes