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ProchlorothrixRANK: GenusTAXONOMY: Bacteria -> Terrabacteria group -> Cyanobacteria/Melainabacteria group -> Cyanobacteria -> Prochlorales -> Prochlorotrichaceae -> Prochlorothrix OVERVIEW: Prochlorothrix is a filamentous organism that divides exclusively by binary fission in one plane and has slight to prominent constrictions at the cross-walls. Cells are longer (3–10 µm) than broad (0.5–1.5 µm in diameter). However, under salt stress (i.e., 25 mM NaCl) cells may enlarge to reach 15 µm in length and 3 µm in width. Thylakoids arranged in layers parallel to the long axis at the periphery of the cytoplasm. Phycobilisomes absent. Motility absent; polar gas vacuoles present; sheaths absent or poorly developed; apical cells undifferentiated (rounded). Lacks N2-fixing ability. Phycobiliproteins (i.e., CPE, C-PC, and APC) absent; chlorophyll a and chlorophyll b present. Zeaxanthin and β-carotene are the major carotenoids. |