Chromatiaceae and Chlorobiaceae are the two families of photosynthetic sulphur bacteria that favour anaerobic conditions for growth while utilizing solar energy and sulphide. Chromatiaceae contain sulphur particles in cells but Chlorobiaceae precipitate them out. The family Rhodospirillaceae is not of any use for H2S removal as they mainly utilize organic material, such as lower fatty acid, as source of hydrogen. But they can be used as efficient mineralizers at pond bottom as they grow in both aerobic and anaerobic conditions as heterotrophic bacteria even in the dark without utilizing solar energy (Singh and Radhika 2001). Photosynthetic bacteria of importance in aquaculture are the
following (Haung 2003):