skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effect of aluminum and zinc on enzyme activities in the green Alga Selenastrum capricorutum

Abstract

Acid rain produced by atmospheric pollution may decrease the pH value of water and increase the availability and potential toxicity of metals in water which have detrimental effects on aquatic organism, including algae, the important component of the primary production, and, thus, the entire aquatic food chain. Recent reviews of the effects of acid rain on freshwater ecosystems have emphasized research interest in soluble trivalent aluminum, although Al is rated low among trace metals in biological importance. On the other hand, zinc is an important trace element for the growth of phytoplankton and the cofactor of some enzymes. The growth response and tolerance of different species of algae to Al and Zn have been reported by Whitton who showed that algal growth would be stimulated by lower levels of the metals and totally inhibited by higher levels. These is little information, however, on the effect of Al on biochemical processes in aquatic organisms. This study investigates the influence of aluminum and zinc on several physioclogical processes in S. capricournutum, a common species of green algal in lake water. Algal growth (dry weight), ATP levels and the activities of several enzymes in the algal cells were measured after the treatment withmore » various concentrations of Al and Zn in culture medium. Special attention is given to the relation between the enzymatic response and algal growth. 15 refs., 2 figs., 1 tab.« less

Authors:
;  [1]
  1. Nanjing Univ. (China)
Publication Date:
OSTI Identifier:
135900
Resource Type:
Journal Article
Resource Relation:
Journal Name: Bulletin of Environmental Contamination and Toxicology; Journal Volume: 55; Journal Issue: 5; Other Information: PBD: Nov 1995
Country of Publication:
United States
Language:
English
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; 54 ENVIRONMENTAL SCIENCES; ACID RAIN; ENVIRONMENTAL EFFECTS; ALUMINIUM; BIOLOGICAL EFFECTS; ZINC; ALGAE; ENZYME ACTIVITY; METALS; BIOLOGICAL AVAILABILITY; PH VALUE; SURFACE WATERS

Citation Formats

Kong, F.X., and Chen, Y.. Effect of aluminum and zinc on enzyme activities in the green Alga Selenastrum capricorutum. United States: N. p., 1995. Web.
Kong, F.X., & Chen, Y.. Effect of aluminum and zinc on enzyme activities in the green Alga Selenastrum capricorutum. United States.
Kong, F.X., and Chen, Y.. Wed . "Effect of aluminum and zinc on enzyme activities in the green Alga Selenastrum capricorutum". United States. doi:.
@article{osti_135900,
title = {Effect of aluminum and zinc on enzyme activities in the green Alga Selenastrum capricorutum},
author = {Kong, F.X. and Chen, Y.},
abstractNote = {Acid rain produced by atmospheric pollution may decrease the pH value of water and increase the availability and potential toxicity of metals in water which have detrimental effects on aquatic organism, including algae, the important component of the primary production, and, thus, the entire aquatic food chain. Recent reviews of the effects of acid rain on freshwater ecosystems have emphasized research interest in soluble trivalent aluminum, although Al is rated low among trace metals in biological importance. On the other hand, zinc is an important trace element for the growth of phytoplankton and the cofactor of some enzymes. The growth response and tolerance of different species of algae to Al and Zn have been reported by Whitton who showed that algal growth would be stimulated by lower levels of the metals and totally inhibited by higher levels. These is little information, however, on the effect of Al on biochemical processes in aquatic organisms. This study investigates the influence of aluminum and zinc on several physioclogical processes in S. capricournutum, a common species of green algal in lake water. Algal growth (dry weight), ATP levels and the activities of several enzymes in the algal cells were measured after the treatment with various concentrations of Al and Zn in culture medium. Special attention is given to the relation between the enzymatic response and algal growth. 15 refs., 2 figs., 1 tab.},
doi = {},
journal = {Bulletin of Environmental Contamination and Toxicology},
number = 5,
volume = 55,
place = {United States},
year = {Wed Nov 01 00:00:00 EST 1995},
month = {Wed Nov 01 00:00:00 EST 1995}
}
  • Algal growth inhibition tests were performed with the unicellular green alga Selenastrum capricornutum and three {sup 14}C-labeled polychlorinated biphenyl (PCB) congeners. Toxicity was related to external aqueous concentrations and additionally to internal algal bound PCB concentrations. Estimates of the concentrations at 50% effectiveness (EC50s) for the three PCB congeners ranged within a factor of 17 when based on measured aqueous concentrations. When based on internal toxicant concentrations the corresponding range was 6.7 to 14.3 mmol/kg wet weight. Thus, changing the basis from external to internal concentrations reduced the range by almost one order of magnitude. Additional toxic cell concentrations ofmore » five monoaromatic compounds and S. capricornutum were calculated from literature data to be in the same order of magnitude as the experimental toxic cell concentrations for the PCBs, whereas EC50 values for all substances ranged by more than four orders of magnitude. The experimental and calculated data indicate that observed differences in the estimated EC50 values were mainly due to differences in bioconcentration behavior rather than to different intrinsic toxicities. These findings are in agreement with the concept of baseline toxicity, meaning that a number of hydrophobic organics exerts their acute toxicity by one relatively nonspecific mode of action.« less
  • The authors have determined the flow of {sup 15}N into free amino acids of the N-limited green alga Selenastrum minutum (Naeg.) Collins after addition of {sup 15}NH{sub 4}{sup +} to aerobic or anaerobic cells. Under aerobic conditions, only a small proportion of the N assimilated was retained in the free amino acid pool. However, under anaerobic conditions almost all assimilated NH{sub 4}{sup +} accumulates in alanine. This is a unique feature of anaerobic NH{sub 4}{sup +} assimilation. The pathway of carbon flow to alanine results in the production of ATP and reductant which matches exactly the requirements of NH{sub 4}{supmore » +} assimilation. Alanine synthesis is therefore an excellent strategy to maintain energy and redox balance during anaerobic NH{sub 4}{sup +} assimilation.« less
  • The effects of selected polycyclic aromatic hydrocarbons (PAHs) on the growth of the green alga Selenastrum capricornutum in three light regimens were examined. In gold fluorescent light, benzo(a)pyrene (BaP) at 12 mg/liter (48 ..mu..mole/liter), benz(a)anthracene (BaA) at 40 mg/liter (175 ..mu..mole/liter), anthracene (A) at 40 mg/liter (224 ..mu..mole/liter), and 13 metabolites of BaP each at 40 ..mu..g/liter had no effect on algal growth. In cool-white fluorescent light, 30% inhibition of algal growth occurred with 0.1 ..mu..mole/liter BaP, 8.0 ..mu..mole/liter BaA, and 40 ..mu..mole/liter A. BaP at 0.16 mg/liter (0.64 ..mu..mole/liter) totally inhibited growth. BaP concentrations an order of magnitude lowermore » inhibited algal growth in fluorescent blacklight. In cool-white light, 5 of 13 metabolites of BaP (each 40 ..mu..g/liter) inhibited algal growth; 3,6-quinone; 6-hydroxy; 9-hydroxy; 3-hydroxy; and 1,6-quinone. Based on these results, PAHs and metabolites of BaP are selectively phototoxic to S. capricornutum due to the incident light intensity below 550 nm.« less
  • In the present study, the impact on membrane integrity of the aromatic hydrocarbons, benzene, toluene, ethylbenzene and three xylene isomers (para, meta, and ortho), collectively referred to as BTEX, was investigated using the green alga, Selenastrum capricornutum. BTEX are water-soluble components of crude oil and gasoline which are known to be toxic to aquatic life. Their impact on membrane integrity was determined by monitoring the release of {sup 14}C-labeled photosynthates from algal cells exposed to benzene and o-xylene. An alternative method utilized a fluorescent dye, uranin (fluorescein sodium salt), which is commonly used as a vital stain. The purpose ofmore » the present study was to evaluate the usefulness and sensitivity of uranin staining as an indicator of the impact of organic pollutants on membrane integrity. The sensitivity of the uranin staining technique was compared to the concentration of BTEX required to inhibit algal growth.« less
  • Certain PAHs are photosensitizers and in the presence of solar radiation can cause toxicity to aquatic plants and animals. The photoinduced toxicity of anthracene to the green alga Selenastrum capricornutum was assessed by the use of flow cytometry to measure cell size, cellular chlorophyll concentration, and cell viability. Anthracene was slightly toxic in the absence of UV-A radiation. The detection of the direct toxicity of anthracene in this study at a concentration of 19 [mu]g/L anthracene resulted from the use of sensitive flow cytometric measures. There was a significant interaction between anthracene and UV-A radiation, which, in combination, caused significantmore » toxic effects on Selenastrum capricornutum. The most sensitive flow cytometric measure of toxicity was the stress index (SI), which was predictive of longer term effects on cell growth. The 28-h EC50 and EC10 and for the SI for Selenastrum capricornutum were 16.1 and 8.3 [mu]g/L anthracene, respectively, at 125 [mu]W/cm[sup 2] UV-A. All combinations for anthracene and UV-A that inhibited algal growth also caused a significantly greater number of nonviable cells. The flow cytometric methods used in this study proved to be sensitive, predictive measures of the direct and photo-induced toxicity of anthracene and UV-A radiation to Selenastrum capricornutum.« less