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
Tamil Nadu cultivated plants and 230 red-listed species. The Gymnosperm diversity of the country is 64 species of which Tamil Nadu has four indigenous species and about 60 introduced species. The Pteridophytes diversity of India includes 1022 species of which Tamil Nadu has about 184 species. Vast numbers of bryophytes, lichen, fungi, algae and bacteria are among the wild plant diversity of Tamil Nadu. Common plant species include the state tree: palmyra palm, eucalyptus, rubber, cinchona, clumping bamboos ("Bambusa arundinacea"), common teak, "Anogeissus latifolia", Indian laurel, grewia, and blooming trees like Indian labumusum, ardisia, and solanaceae. Rare and unique plant life includes