Deep sea vent: Difference between revisions
No edit summary |
|||
| Line 19: | Line 19: | ||
==Who lives there?== | ==Who lives there?== | ||
=== | ===Microbes Present=== | ||
Many different kinds of archaea and chemolithotrophic bacteria live here. Studies have classified entire archaeal communities in deep-sea hydrothermal vent chimney structures. (http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939) Scientists discovered deep-sea hydrothermal vents in 1979 and many microorganisms have been isolated from these deep-sea samples. | |||
The majority of the microbes that live in this niche include hyperthermophiles and thermophiles from both the bacterial and archaeal domains. Recent studies have shown and increasing number of unclassified and uncultivated thermophiles. This leads scientists to believe that these communities are very phylogenetically diverse. | |||
Major types of bacteria that live near these vents are mesophilic sulfur bacteria. These bacteria are able to achieve high biomass densities due to their unique physiological adaptations. For example, Beggiatoa spp. is able to carry an internal store of nitrate as an electron acceptor that helps with the harvesting of free sulfide in the upper sediment region of the vents. Page 70 | |||
Some bacterial samples contained bacterial specific to the genera Thermotoga and Thermosipho. An analysis of a specific morphotype revealed that it was an anaerobic autotrophic sulfur and thiosulfate-reducing strain of bacteria but did not belong to any known phyla. It belongs to a branch between the orders Aquificales and Thermotogales. The new bacterium was named Desulfurobacterium thermolithotrophicum. | |||
Recent studies have shown that sizable populations of extremely halophilic archaea inhabit the inside structures of black smoker chimneys. These bacteria belong to the genera Halomonas and Marinobacter. The existence of these halophilic archaea is probably due to the brines/salt deposits found in deep-sea hydrothermal systems. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939 | |||
Based on microbiological, geochemical, and geophysical observations, some scientists believe that a whole new biosphere exists beneath active hydrothermal vents. This idea is supported by the detection of microbial rDNA in the black smoker vent water. However it is difficult to conclude if there is a true microbial population living under black smoker vents because deep ocean water is continuously being filtered underneath sea floor basalts and pumped out of black smoker vents. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939 | |||
===Are there any other non-microbes present?=== | ===Are there any other non-microbes present?=== | ||
Revision as of 22:11, 27 August 2008
This template is a general guideline of how to design your site. You are not restricted to this format, so feel free to make changes to the headings and subheadings and to add additional sections as appropriate.
Description of Niche
Where located?
Physical Conditions?
What are the conditions in your niche? Temperature, pressure, pH, moisture, etc.
Influence by Adjacent Communities (if any)
Is your niche close to another niche or influenced by another community of organisms?
Conditions under which the environment changes
Do any of the physical conditions change? Are there chemicals, other organisms, nutrients, etc. that might change the community of your niche.
Who lives there?
Microbes Present
Many different kinds of archaea and chemolithotrophic bacteria live here. Studies have classified entire archaeal communities in deep-sea hydrothermal vent chimney structures. (http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939) Scientists discovered deep-sea hydrothermal vents in 1979 and many microorganisms have been isolated from these deep-sea samples.
The majority of the microbes that live in this niche include hyperthermophiles and thermophiles from both the bacterial and archaeal domains. Recent studies have shown and increasing number of unclassified and uncultivated thermophiles. This leads scientists to believe that these communities are very phylogenetically diverse. Major types of bacteria that live near these vents are mesophilic sulfur bacteria. These bacteria are able to achieve high biomass densities due to their unique physiological adaptations. For example, Beggiatoa spp. is able to carry an internal store of nitrate as an electron acceptor that helps with the harvesting of free sulfide in the upper sediment region of the vents. Page 70
Some bacterial samples contained bacterial specific to the genera Thermotoga and Thermosipho. An analysis of a specific morphotype revealed that it was an anaerobic autotrophic sulfur and thiosulfate-reducing strain of bacteria but did not belong to any known phyla. It belongs to a branch between the orders Aquificales and Thermotogales. The new bacterium was named Desulfurobacterium thermolithotrophicum.
Recent studies have shown that sizable populations of extremely halophilic archaea inhabit the inside structures of black smoker chimneys. These bacteria belong to the genera Halomonas and Marinobacter. The existence of these halophilic archaea is probably due to the brines/salt deposits found in deep-sea hydrothermal systems. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939
Based on microbiological, geochemical, and geophysical observations, some scientists believe that a whole new biosphere exists beneath active hydrothermal vents. This idea is supported by the detection of microbial rDNA in the black smoker vent water. However it is difficult to conclude if there is a true microbial population living under black smoker vents because deep ocean water is continuously being filtered underneath sea floor basalts and pumped out of black smoker vents. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11472939
Are there any other non-microbes present?
Plants? Animals? Fungi? etc.
Do the microbes that are present interact with each other?
Describe any negative (competition) or positive (symbiosis) behavior
Do the microbes change their environment?
Do they alter pH, attach to surfaces, secrete anything, etc. etc.
Microbe Metabolism Affecting the Environment
The primary source of metabolism for providing food is through animal-bacteria symbiosis. These bacteria are typically chemolithotrophic bacteria. In many worms, they have a layer of tissue called trophosome that fills the body cavity and allows these chemolithotrophic bacteria to live symbiotically in these trophosomes where they can oxidize sulfide. Enzymes in the trophosome also have the capacity to oxidize hydrogen sulfide. The energy produced can be used to drive net fixation of CO2 and to reduce nitrate to ammonia. A mechanism to avoid poisoning aerobic respiration by hydrogen sulfide is protected by sulfide binding proteins in the blood. The idea is to prevent as little free floating sulfide as possible.
Many invertebrates also show a range of O2 consumption that is similar to species that live closer to the surface. Besides a difference in thermal effects, there is no decline of O2 consumption, strongly indicating the importance of endosymbionts. Other organisms, such as deep sea pelagic animals will show a lower O2 consumption due to its inability to swim. If they lose the ability to swim, they can save that energy and lower their O2 consumption.
Current Research
Enter summaries of the most recent research. You may find it more appropriate to include this as a subsection under several of your other sections rather than separately here at the end. You should include at least FOUR topics of research and summarize each in terms of the question being asked, the results so far, and the topics for future study. (more will be expected from larger groups than from smaller groups)
References
Edited by [Vicky Chen , Vicky Kuo , Ban Lam , Pan Lu , Tam Pham , Cassie Tom], students of Rachel Larsen
