Purple sulfur bacteria Purple sulfur bacteria The purple sulfur bacteria (PSB) are part of a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in stratified water environments including hot springs, stagnant water bodies, as well as microbial mats in intertidal zones. Unlike plants, algae, and cyanobacteria, purple sulfur bacteria do not use water as their reducing agent, and therefore do not produce oxygen. Instead, they can use sulfur in the form of sulfide, or thiosulfate (as well, some species can use H, Fe, or NO) as the electron donor in
Red algae 2005 have provided evidence that is in agreement for monophyly in the Archaeplastida (including red algae). However, other studies have suggested Archaeplastida is paraphyletic. , the situation appears unresolved. Below are other published taxonomies of the red algae using molecular and traditional alpha taxonomic data; however, the taxonomy of the red algae is still in a state of flux (with classification above the level of order having received little scientific attention for most of the 20th century). A major research initiative to reconstruct the Red Algal Tree of Life (RedToL) using phylogenetic and genomic approaches is funded by the National