The role of photosynthesis in the physiology of ochromonas

✍ Scribed by Myers, Jack ;Graham, Jo-Ruth

• Publisher: Wiley (John Wiley & Sons)
• Year: 1956
• Tongue: English
• Weight: 780 KB
• Volume: 47
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030470307

✦ Synopsis

Among the algae and related protists there are found the nutritional extremes of both autotrophy and heterotrophy. Chlamydonzonas moewusii (Lewin, 5 0 ) and several of the blue-green algae (Kratz, '54) are obligate autotrophs in the sense that they will utilize for growth no carbon source other than carbon dioxide. At the other extreme there are colorless species such as Prototheca (Barker, '36) and the induced and permanently apochlorotic forms of Euglena (Hutner and Provasoli, '51) which are limited to a heterotrophic nutrition. Many of the algae which have been studied may grow either autotrophically o r heterotrophically although in Chlorella and Scenedesmus, and probably rather commonly, photosynthesis will support a rate of growth higher than can be attained on any organic substrate in the dark (Myers, '51). From such extreme and intermediate cases one is led to expect a complete spectrum of relationships between autotrophic and heterotrophic nutrition within the algae. Of particular interest in this connection is Ochromonas.

The chrysomonad Ochromoncrs rnalharnensis was isolated by Chen and described by Pringsheim ('52) as a nutritionally versatile organism which is saphrotrophic, phagotrophic, and phototrophic. It is a flagellate protozoan considered also an alga by virtue of its brownish-green pigmentation. A defined medium for the Pringsheim strain and several other isolates Aided by Grant G259 from the National Science Foundation.