Kappaphycus alvarezii as semirefined carrageenan. "K. alvarezii" is affected by ice-ice, a disease that severely reduces its yield. This alga is an introduced species and a noxious aquatic weed in Hawaii. Kappaphycus alvarezii Kappaphycus alvarezii, the elkhorn sea moss, is a species of red algae. It is one of the most important commercial sources of carrageenans, a family of gel-forming, viscosifying polysaccharides. Farming methods affect the character of the carrageenan that can be extracted from the seaweed. This alga grows to two meters long and is green or yellow in color. It is very fast-growing, known to double its biomass in 15
Purple bacteria Purple bacteria Purple bacteria or purple photosynthetic bacteria are proteobacteria that are phototrophic, that is, capable of producing their own food via photosynthesis. They are pigmented with bacteriochlorophyll "a" or "b", together with various carotenoids, which give them colours ranging between purple, red, brown, and orange. They may be divided into two groups – purple sulfur bacteria (Chromatiales, in part) and purple non-sulfur bacteria (Rhodospirillaceae). In a 2018 paper, it has been suggested purple bacteria be used as a biorefinery. Purple bacteria are mainly photoautotrophic, but are also known to be chemoautotrophic and photoheterotrophic. They can be mixotrophs, capable of