ISSN:
1432-072X
Keywords:
δ-Aminolevulinic acid
;
Chlorella pyrenoidosa
;
Chlorophyll biosynthesis
;
Levulinic acid
;
Vanadium
;
Vanadium effect
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In a series of experiments, it is demonstrated that the trace element vanadium (4·10-7 g-at/l as NH4VO3) has a considerable positive influence on the synthesis of δ-aminolevulinic acid (δ-ALA) in the autotrophically growing green algaChlorella pyrenoidosa, the effect being visible by an enhanced output of the amino acid into the culture medium in presence of levulinic acid (LA). The level of intracellularly accumulated δ-ALA, however, is not changed in presence of the metal. The V-effect on exogenous found δ-ALA is suppressed, when LA is added to the nutrient medium at low pH (pH 5), although V-uptake into the algal cells is not disturbed by LA. As demonstrated in culture media with various nitrogen sources (urea, partially hydrolized urea, ammonium salts), the development of the pH during the cultivation time is important for the presentation of the V-effect on δ-ALA. It is suggested that vanadium acts as a catalyst in the conversion of 4,5-dioxovaleric acid to δ-ALA by transamination.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00689350
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