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Biochemical Taxonomy of Symbiotic Chlorella Strains from Paramecium and Acanthocystis *

1990; Thieme Medical Publishers (Germany); Volume: 103; Issue: 2 Linguagem: Inglês

10.1111/j.1438-8677.1990.tb00139.x

0932-8629

Erich Kessler, Volker A. R. Huss,

Marine and coastal ecosystems

Abstract Biochemical and physiological characters of 5 symbiotic Chlorella strains, 4 of them from Paramecium (Ciliata) and one from Acanthocystis (Rhizopoda, Heliozoa) , were studied. Four strains (3 from Paramecium and one from Acanthocystis ) belong to the same species. This is characterized by the presence of hydrogenase, no formation of secondary carotenoids, no growth on mannitol, requirements for thiamine and vitamin B 12 , and a G + C content of the DNA of 66.4–68.4 mol%; the limits of growth are at pH 5.5, at up to 1% NaCl, and at 26–30°C. The strains are somewhat heterogeneous in their utilization of inorganic nitrogen sources: only two of them are able to use nitrate, whereas all can grow with nitrite and ammonium. Thus, in two strains the nitrate‐reducing system — in contrast to nitrite reductase — seems to be defective. Another strain, which has been claimed to be from Paramecium , belongs to C. protothecoides .