Isolation, purification and evidence for a halophilic nature of the blue-green alga Aphanothece halophytica Fremy (Chroococcales)

Abstract

An axenic culture of an extremely halotolerant blue-green alga, Aphanothece halophytica (Chroococcaies), was obtained following a multi-step purification procedure. Effectiveness of purification procedures as a function of hypersalinity is discussed. Development of a defined medium and growth in NaCl up to saturation is reported. Changes in cellular morphology are concomitant to changes in salinity and other physico-chemical parameters. Lysis of the alga in distilled water and in media of less than 1 m NaCl, as well as failure of KCL, LiCl and CsCl to substitute for NaCl support the view that the alga is perhaps halophilic rather than only halotolerant.