User:Shirley.Chen.27/sandbox

User:Chkathryn/sandbox

Original - "Purple sulfur bacteria"

Paragraph 1 from the lead

The purple sulfur bacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in hot springs or stagnant water. Unlike plants, algae, and cyanobacteria, they do not use water as their reducing agent, so do not produce oxygen. Instead, they use hydrogen sulfide, which is oxidized to produce granules of elemental sulfur. This, in turn, may be oxidized to form sulfuric acid.

Paragraph 4 from the lead

The most favorable lakes for the development of purple sulfur bacteria are meromictic (permanently stratified) lakes. Meromictic lakes stratify because they have denser (usually saline) water in the bottom and less dense (usually fresh water) nearer the surface. If sufficient sulfate is present to support sulfate reduction, the sulfide, produced in the sediments, diffuses upward into the anoxic bottom waters, where purple sulfur bacteria can form dense cell masses, called blooms, usually in association with green phototrophic bacteria.

Edit #2 - based on peer review:

Paragraph 1 from the lead

The purple sulfur bacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in hot springs or stagnant water. Unlike plants, algae, and cyanobacteria, they do not use water as their reducing agent, therefore do not produce oxygen. Instead, they oxidize sulfides into granules of elemental sulfur, which can be further oxidized to sulfate and used by plants, the primary producers of the world. Thus, purple sulfur bacteria contribute to the global sulfur cycle.

Paragraph 4 from the lead

Purple sulfur bacteria thrive in meromictic lakes. If sufficient sulfate is present to support sulfate reduction, the sulfide produced in the sediments will diffuse upward into the anoxic bottom waters. This allows purple sulfur bacteria to form dense cell masses (blooms), usually in association with green phototrophic bacteria.

*Note to reviewer: the following section comes immediately after the lead

Growth in meromictic lakes
Meromictic lakes are permanently stratified lakes produced by a gradient of saline concentrations. The highly salinated bottom layer is separated from the top layer of fresh water by the chemocline, where the salinity changes drastically. Due to the large difference in density, the upper and lower layers do not mix, resulting in an anoxic environment below the chemocline. This anoxic environment with light and sufficient sulfide availability is ideal for purple sulfur bacteria.

A study done at the Mahoney Lake suggested that purple sulfur bacteria contributes to the recycling of the inorganic nutrient, phosphorous. The upwelling of purple sulfur bacteria into the top layer of water creates a source of bound phosphorous, and phosphatase activity releases these phosphorous into the water. The soluble phosphorous is then incorporated into heterotrophic bacteria for use in developmental processes. In this way, purple sulfur bacteria participates in the phosphorous cycle and minimizes nutrient loss.

Article Evaluation - Tutorial (EOSC 475)
Article on oceanic dolphin has working links.