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Sulphate Uptake in Two Mutants of Chlorella vulgaris with High and Low Sulphur Amino Acid Content
Author(s) -
PASSERA CALVINO,
FERRARI GIOVANNI
Publication year - 1975
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1975.tb03913.x
Subject(s) - cycloheximide , chlorella vulgaris , methionine , mutant , sulfur , amino acid , cysteine , biochemistry , strain (injury) , chlorella , chemistry , biology , sulfur metabolism , algae , botany , metabolism , protein biosynthesis , gene , enzyme , organic chemistry , anatomy
Two mutants of Chlorella vulgaris characterized by higher and lower content of sulphur amino acids compared with the wild strain were assayed for the efficiency of the sulphate uptake mechanism. In both mutants uptake exhibited positive cooperation kinetics and was strongly stimulated by sulphate starvation. Stimulation was depressed by cysteine and to a higher extent by methionine. Mutations affected the uptake efficiency concordantly with the level of sulphur amino acids. Addition to the starved strains of sulphate or chromate reduced the induced transport to the lower values of the non‐starved strains. Addition of cycloheximide during the induction period prevented a further enhancement of transport without depressing the attained rate in the low sulphur mutant; it was followed by a rapid fall to the non‐induced rate in the high sulphur mutant.