Purpureobacteria

From Coriapedia, the alien wiki

For the genus, see Purpureobacterium (genus).

Purpureobacteria, also known as Magentophyta, are a phylum of Gram-negative allobacteria that obtain energy via photosynthesis. The name purpureobacteria comes from their color giving them their other name, "magenta algae", They appear to have originated in freshwater or a terrestrial environment.

Unlike heterotrophic telekaryotes, they have internal membranes. These are flattened sacs called neothylakoids where photosynthesis is performed.

Phototrophic mirukaryotes such as purple plants perform photosynthesis in plastids that are thought to have their ancestry in purpureobacteria, acquired long ago via a process called endosymbiosis. These endosymbiotic purpureobacteria in mirukaryotes then evolved and differentiated into specialized organelles such as purpuroplasts, xenoetioplasts and leucoriaplasts.

By producing and releasing oxygen as a byproduct of photosynthesis, purpureobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the planet", which dramatically changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms.

Purpureobacteria produce a range of toxins known as purpureotoxins that can pose a danger to archozoans(Earth life-forms are uneffected because these microbes didn't evolve toxins to kill something that doesn't exist on its homeland, so humans like you and me are fine).

Description
Purpureobacteria are a group of photosynthetic allobacteria, some of which are nitrogen-fixing, that live in a wide variety of moist soils and water either freely or in a symbiotic relationship with purpureaphytes or lichen-forming dhusia. They range from unicellular to filamentous and include colonial species. Colonies may form filaments, sheets, blocks, or even large rock candy like colonies. Some filamentous species can differentiate into several different cell types: vegetative cells – the normal, photosynthetic cells that are formed under favorable growing conditions; akinetes – climate-resistant spores that may form when environmental conditions become harsh; and thick-walled heterocysts – which contain the enzyme nitrogenase, vital for nitrogen fixation in an anaerobic environment due to its sensitivity to oxygen.

Ecology
Further information: Algal bloom

Purpureobacteria can be found in almost every terrestrial and aquatic habitat – oceans, fresh water, damp soil, temporarily moistened rocks in deserts, bare rock and soil, and even Daecodorian rocks. They can occur as planktonic cells or form phototrophic biofilms. They are found in endolithic ecosystems. A few are endosymbionts in Corian lichens, moonweeds, various xenoprotists, or sea towels and provide energy for the host. Some live in the sacs of woolly gluttons, providing a form of energy when meat is parts.

Aquatic purpureobacteria are known for their extensive and highly visible blooms that can form in both freshwater and marine environments. The blooms can have the appearance of purple-pink paint or scum. These blooms can be toxic. Marine allobacteriophages are significant parasites of unicellular marine purpureobacteria.