Thiodictyon
Thiodictyon is a genus of gram-negative bacterium classified within purple sulfur bacteria (PSB). T. elegans forms "netlike aggregates under certain culture conditions." It is obligately phototrophic and strictly anaerobic. T. bacillosum does not form netlike aggregates, only clumps. "Ca. T. syntrophicum" grows best under micro-oxic and low light conditions. There has only been one successful enrichment of "Ca. T. syntrophicum"; "Ca. T. syntrophicum" strain Cad16T. "Ca. T. intracellulare" is reported in 2021 as a symbiont of Pseudoblepharisma tenue. It has lost a great portion of its genome including known genes for sulfur dissimilation, but the remaining sequence place it quite close to "Ca. T. syntrophicum". Classification Thiodictyon belongs to the family Chromatiaceae and class Gammaproteobacteria. "Ca. T. syntrophicum" is known to be related to the genera Lamprocystis, Thiocystis and Thiocapsa. Strain Cad16T was previously assigned to the genus Lamprocystis, but was recently reassigned to the genus Thiodictyon by Peduzzi et al. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) was used to separate Cad16T from Lamprocystis due to differences in cell morphology/arrangement, caretenoid groups and chemolithotrophic growth; all of which are important factors used to consider Cad16T a member of the genus Thiodictyon rather than the genus Lamprocystis.