Chlorobaculum tepidum

Like other green sulfur bacteria C. tepidum requires light and specific compounds to perform anoxygenic photosynthesis. To fulfill their metabolic requirements, they reside primarily in anaerobic sulfur rich environments such as anaerobic levels of stratified lakes and lagoons, anaerobic levels of layered organic bacterial mats, and in hot springs where there is abundant sulfur. Within anaerobic sediment layers C. tepidum is able to couple carbon and sulfur cycling in a metabolically favorable way. == Photosynthetic mechanism ==

As it was mentioned before, C. tepidum performs anoxygenic photosynthesis. Within each cell there are 200–250 chlorosomes Light energy is harvested by the chlorosomes and used in conjunction with H2, reduced sulfur compounds, or ferrous iron to perform redox reactions and provide energy to fix CO2 via the reverse tricarboxcylic acid cycle. ==Genome structure==

Chlorobaculum tepidum contains a genome that contains 2.15 Mbp, within there are a total of 2,337 genes (of these genes, there are 2,245 protein coding genes and 56 tRNA and rRNA coding genes). It's synthesis of chlorophyll a and bacteriochlorophylls a and c make it a model organism used to elucidate the biosynthesis of bacteriochlorophylls c. Present in the genome of C. tepidum are a multitude of genes that protect the bacterium against the presence of oxygen. The fact that such a large part of the genome is used to encode for protections against oxygen points to the possibility that C. tepidum spent a long period of its evolutionary history in proximity to oxygen, and therefore needed pathways that ensured that living in the presence of oxygen would not substantially harm the bacterium. Several of its carotenoid metabolic pathways (including a novel lycopene cyclase) have similar counterparts in cyanobacteria. ==References==