User:Fensk110/Green sulfur bacteria

Article Draft
This article could probably use some more information about the habitat. The carbon fixation section could probably be expanded upon and made more understandable for those not in STEM. Some of the different types of bacteria could be explained or described, probably the more abundant ones. The relevance or importance of green sulfur bacteria to ecosystems could probably be added or expanded upon. Maybe the history of green sulfur research could also be included.

Things to do/fix:

- expand habitat section

-clean up characteristics section if possible (make a table maybe?)

-edit carbon fixation section for accessibility

-expand mixotrophy

-expand N fixation

-add section comparing to purple sulfur bacteria?

-add section on certain types?

-add more photos?

Characteristics (edited)
Green sulfur bacteria are gram-negative rod or spherical shaped bacteria. Some types of green sulfur bacteria have gas vacuoles that allow for movement. They are photolithoautotrophs, and use light energy and reduced sulfur compounds as the electron source. Electron donors include H2S, S and H2. The major photosynthetic pigment in these bacteria is Bacteriochlorophylls c or d in green species and e in brown species, and is located in the chlorosomes and plasma membranes. Cholorsomes are a unique feature that allow them to capture light in low-light conditions. (see google doc for sources)

Habitat (edited)
The majority of green sulfur bacteria are mesophilic, preferring moderate temperatures, and all live in aquatic environments. They require anaerobic conditions and reduced sulfur; they are usually found in the top millimeters of sediment. They are capable of photosynthesis in low light conditions.

The Black Sea, an extremely anoxic environment, was found to house a large population of green sulfur bacteria at about 100 m depth. Due to the lack of light available in this region of the sea, most bacteria were photosynthetically inactive. The photosynthetic activity detected in the sulfide chemocline suggests that the bacteria need very little energy for cellular maintenance.

A species of green sulfur bacteria has been found living near a black smoker off the coast of Mexico at a depth of 2,500 m in the Pacific Ocean. At this depth, the bacterium, designated GSB1, lives off the dim glow of the thermal vent since no sunlight can penetrate to that depth.

Green sulfur bacteria have also been found living on coral reef colonies in Taiwan, they make up the majority of a "green layer" on these colonies. They likely play a role in the coral system, and there could be a symbiotic relationship between the bacteria and the coral host. The coral could provide an anaerobic environment and  a source of carbon for the bacteria. The bacteria can provide nutrients and detoxify the coral by oxidizing sulfide.

One type of green sulfur bacteria, Chlorobium tepidum, has been found in sulfur springs. These organisms are thermophilic, unlike most other green sulfur bacteria. (see google doc for sources)