L. Simon et al., Effects of zirconium on the growth and photosynthetic pigment composition of Chlorella pyrenoidosa green algae, J PLANT NUT, 24(1), 2001, pp. 159-174
The effects of zirconium (Zr) were investigated on the growth rate, dry mat
ter accumulation, and elemental and photosynthetic pigment composition of C
hlorella pyrenoidosa green algae. Algae were treated with 0.1-50 muM (appro
ximate to0.009-4.561 mg dm(-3)) of Zr; inorganic compounds (Zr oxychloride,
Zr nitrate) and organic chelates (Zr ascorbate or Zr citrate) were applied
. All Zr compounds displayed only a slight insignificant inhibitory effect
on the growth rate of algae. Treatment of algae with 1 muM Zr las Zr ascorb
ate, a water soluble pH stable chelate) slightly stimulated and 5-50 muM Zr
slightly inhibited the dry matter accumulation of Chlorella. Zirconium con
centration in the nutrient solution decreased rapidly during the algae prop
agation, and Chlorella cells accumulated significant amounts of Zr. In the
case of 1 muM Zr (Zr ascorbate) treatment, 60.6 mug g(-1) Zr was found in t
he washed cells; after 50 muM Zr application this value was 441 mug g(-1) Z
r. Zirconium treatment reduced the P, Mg, Cu, anti Ti concentrations in alg
ae cells, and the concentration of Fe, Mn, and partly Zn was enhanced. Chlo
rophyll a, chlorophyll b, xanthophyll, and carotenoid concentrations were e
qually reduced by 13-33% in Zr-treated cultures. Zirconium treatment change
d the chlorophyll a:chlorophyll b ratio and caused appearance of several ne
w chlorophyll derivatives in Chlorella.