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Effects of Some Metabolic Inhibitors on the Pigments of Euglena gracilis in an Acidic Medium
Author(s) -
GREENBLATT CHARLES L.,
SHARPLESS NORMAN E.
Publication year - 1959
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1959.tb04365.x
Subject(s) - euglena gracilis , euglena , fluoroacetate , chemistry , pigment , pheophytin , darkness , dcmu , dinitrophenol , chloroplast , biochemistry , biophysics , photosystem ii , photochemistry , biology , photosynthesis , botany , organic chemistry , gene
SYNOPSIS. Darkness and O 2 ‐lack promote formation of a pheophytin‐like pigment from chlorophyll in Euglena gracilis in an acidic medium. Dinitrophenol (DNP) produces similar but more drastic pigment alterations in aerated and illuminated cells. The extent of pigment decay was dependent on DNP concentration and external pH. Since volume expansion and inhibition of the contractile vacuole were also noted, it is suggested that pheophytin formation is secondary to hydrogen ion influx from the external medium. Major structural alterations of the chloroplast accompanied the pigment changes. Pentachlorophenol, iodoacetamide, Na fluoride, and Na azide produced similar pigment changes. Malonic acid and fluoroacetate were ineffective under the conditions described. However, in the dark, cells treated with fluoroacetate formed pheophytin rapidly. These effects are discussed in relation to the maintenance of intracellular [H + ].