#chlorobiota

Chloroflexota propaganda here

Chlorobiota propaganda here

Group: Hydrobacteria; FCB Group

Gram-stain: Negative

Etymology: For Chlorobium limicola. From the Greek "chloros", meaning "yellowish green", and "bios", meaning "life", because the bacteria in this phylum are green.

About: Known as the "green sulfur bacteria", Chlorobiota are sulfur-oxidizing photoautolithotrophs that photosynthesize using green bacteriochlorophylls. They are obligate anaerobes, and thrive in anoxic environments with high concentrations of sulfide. This includes hot springs, as well as sediments, and some freshwater lakes and ponds. They use compounds such as sulfide, thiosulfate, and elemental sulfur as electron donors, and are carbon-fixing. In certain aquatic environments, they may be responsible for up to 83% of carbon fixation annually, making them a critical member of the ecosystem. Some Chlorobiota also fix nitrogen.

Thanks to their special light-harvesting antennae adaptations, Chlorobiota is a phylum of extremely optimized phototrophs. They can grow in very diminished light conditions where no other photosynthetic bacteria can survive. A single Chlorobiota cell may contain over 50 million molecules of bacteriochlorophyll, spread among their various antennae, in structures called "chlorosomes". The cell shape is therefore also optimized for photosynthesis, since Chlorobiota are able to stick out antennae like tiny roots or branches, maximizing exposure to light.

Some Chlorobiota are unique for their ability to reproduce via ternary fission. This is in contrast to binary fission, the method used by most bacteria: instead of dividing in half, in ternary fission the nucleus splits into three. The cytoplasm then separates to create three daughter cells.

Chlorobiota are non-motile (i.e. incapable of movement), except for the species Chloroherpeton thalassium, who move by flexing and gliding. Despite many similarities in biochemistry and function, Chlorobiota are not closely related to the other major phyla of photosynthetic bacteria, such as Chloroflexota and Cyanobacteriota.