On the selection for heavy metal tolerance in diatoms from the Derwent estuary, Tasmania

1981 ◽  
Vol 32 (4) ◽  
pp. 555 ◽  
Author(s):  
NS Fisher
Keyword(s):  
Metal Uptake ◽  
Growth Response ◽  
Metal Tolerance ◽  
Skeletonema Costatum ◽  
Heavy Metal Tolerance ◽  
Copper Tolerance ◽  
Lag Phase ◽  
Copper And Zinc ◽  
Clonal Cultures ◽  
Selection For

To assess the metal tolerance of phytoplankton from the polluted Derwent estuary in Tasmania, unialgal clonal cultures of three marine diatoms were established from recent isolates. Skeletonema costatum, Melosira moniliformis, and Gyrosigma sp, were exposed to varying levels of copper and zinc and metal uptake and growth response were monitored. Cells of S. costatum, the only species for which direct comparisons were possible, appeared to have greater zinc, but not copper, tolerance than had S. costatum cells isolated from cleaner waters. Unlike the other species, Gyrosigma sp. responded to zinc stress with an extended lag phase, followed by apparent recovery. Uptake of copper and zinc by these species did not significantly differ from that of more sensitive cells. In the Derwent water from which the cells were isolated, the total dissolved copper concentration was 1763 nM, with only 69 nM being polarographically labile, while 84% of the total dissolved zinc (concn 1805 nM) was labile. It appears that it is the labile metal, rather than total metal, which provides selection pressure for metal tolerance, presumably because only this fraction is available for algal uptake.

Overcoming the Bacteriostatic Effects of Heavy Metals on A. thiooxidans Direct Bioleaching of Saprolitic Ni Laterite Ores

2015 ◽  
Vol 1130 ◽  
pp. 263-267 ◽  
Author(s):  
Hee Chan Jang ◽  
Marjorie Valix
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Stress ◽  
Lag Phase ◽  
Tolerance Index ◽  
Acid Generation ◽  
Laterite Ores ◽  
Laterite Ore

In this study, the adaptation of A. thiooxidans to heavy metals leached from saprolitic Ni laterite ores was performed by gradual acclimatisation. The bacteria was cultivated in heavy metals (Ni, Co, Fe, Mg, Cr and Mn) with total concentrations of 2400 to 24000 ppm equivalent to total dissolution of 1 to 10% (w/v) pulp densities of the saprolitic Ni laterite ore. Adaptation evolution mapped from its tolerance index was found to be dependent on metal concentration, acid generation, and period of adaptation. Bio-stimulation of cell growth and acid production was promoted by heavy metal stress on the bacteria. Pre-established heavy metal tolerance of the bacteria improved the leaching rate in its early phase; 20% and 7% increase in Ni and Co metal recoveries were observed in using adapted bacteria. However heavy metal tolerance was also achieved by the bacteria during the leaching process, albeit delayed by a lag phase. These results confirm the robust nature and suitability of A. thiooxidans in direct biomining of Ni ores.

Uptake and Effect of Cations on Lichen Metabolism

1984 ◽  
Vol 16 (2) ◽  
pp. 173-188 ◽  
Author(s):  
D. H. Brown ◽  
R. P. Beckett
Keyword(s):  
Heavy Metal ◽  
Metal Uptake ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Uptake ◽  
Growth Morphology ◽  
Competing Cations ◽  
Kinetics Of Uptake ◽  
Kinetics Of ◽  
Lichen Growth

AbstractHeavy metal uptake by lichens is briefly reviewed in terms of the trapping of paniculate material and the uptake of soluble cations. The kinetics of uptake to extracellular sites and intracellular carrier-mediated incorporation into cells are compared and the effects of competing cations and the energetics of the processes considered. The influence of heavy metals on lichen growth, morphology and physiology are reviewed emphasizing recent reports showing the greater sensitivity of cyanobacterial compared with chlorophycean lichens, the induction of heavy metal tolerance in the field and laboratory in Peltigera species, and alterations in intracellular cadmium uptake kinetics by some, but not all, tolerant Peltigera populations.

Heavy Metal Tolerance in Algae Isolation from Polluted Lakes Near the Sudbury, Ontario Smelters

1973 ◽  
Vol 8 (1) ◽  
pp. 178-201 ◽  
Author(s):  
P.M. Stokes ◽  
T.C. Hutchinson ◽  
K. Krauter
Keyword(s):  
Heavy Metals ◽  
Growth Response ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Toxic Heavy Metals ◽  
Total Inhibition ◽  
Nickel Copper ◽  
Ecological Implications ◽  
The Media ◽  
High Silver

Abstract The phytoplankton flora of lakes close to the Sudbury smelters is poor both in species and in numbers. The lakes have abnormally high levels of several toxic heavy metals, including nickel and copper. Algal isolates were obtained from two lakes which contained up to 3 ppm of nickel and 0.7 ppm of copper in solution. These isolates were found to be tolerant to higher levels of nickel, copper and silver than were laboratory strains. Their growth response to metals in the medium is distinctive and different from that of the lab strains. Lab strains of Saenedesmus and Chlorella stop growing at 0.1 ppm Cu and 0.5 ppm Ni. “Adapted” lake strains of Saenedesmus, however, continue to grow up to 1.0 ppm Cu and 3.0 ppm Ni. “Adapted” strains of Chlorella stop growing at 0.4 ppm Cu. Both of the “adapted” lake isolates showed a gradually decreasing growth rate with increasing concentrations of metals, whereas the lab strains showed total inhibition at a low metal concentration. Lab and lake strains both take up copper. The uptake is linear with concentration in the media. The lake isolates continued growth until a Cu concentration of 2400+ ppm was reached (on dry t. basis). This suggests a mechanism of metal tolerance rather than one of exclusion as means of survival. The ecological implications of these adaptations to high levels of toxic metals are discussed, especially the finding that the tolerant algae are adapted to high silver levels, even though silver is not a pollutant in the lakes.

scholarly journals Plasmid persistence: costs, benefits, and the plasmid paradox

2018 ◽  
Vol 64 (5) ◽  
pp. 293-304 ◽  
Author(s):  
Amanda C. Carroll ◽  
Alex Wong
Keyword(s):  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Extrachromosomal Dna ◽  
Nutrient Sources ◽  
Transfer Rates ◽  
Domains Of Life ◽  
Dna Elements ◽  
Selection For ◽  
Plasmid Genes ◽  
Over Time

Plasmids are extrachromosomal DNA elements that can be found throughout bacteria, as well as in other domains of life. Nonetheless, the evolutionary processes underlying the persistence of plasmids are incompletely understood. Bacterial plasmids may encode genes for traits that are sometimes beneficial to their hosts, such as antimicrobial resistance, virulence, heavy metal tolerance, and the catabolism of unique nutrient sources. In the absence of selection for these traits, however, plasmids generally impose a fitness cost on their hosts. As such, plasmid persistence presents a conundrum: models predict that costly plasmids will be lost over time or that beneficial plasmid genes will be integrated into the host genome. However, laboratory and comparative studies have shown that plasmids can persist for long periods, even in the absence of positive selection. Several hypotheses have been proposed to explain plasmid persistence, including host-plasmid co-adaptation, plasmid hitchhiking, cross-ecotype transfer, and high plasmid transfer rates, but there is no clear evidence that any one model adequately resolves the plasmid paradox.

Comparative studies on the seedling copper tolerance of various hexaploid wheat varieties and of spelt in soil with a high copper content and in hydroponic culture

2003 ◽  
Vol 51 (2) ◽  
pp. 199-203 ◽  
Author(s):  
A. F. Bálint ◽  
G. Kovács ◽  
J. Sutka
Keyword(s):  
Heavy Metal ◽  
Copper Content ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Hydroponic Culture ◽  
Copper Tolerance ◽  
High Copper ◽  
High Copper Content ◽  
Hydroponic Cultures ◽  
Physiological Tests

On areas used for agriculture copper toxicity is one of the most important forms of heavy metal pollution, especially where field crops are to be grown in fields previously used as orchards or vineyards, treated for a long period with pesticides containing copper. Only varieties with good tolerance of soil with a high copper content should be grown on such areas. The selection of copper-tolerant varieties is complicated, however, by the fact that it is difficult to study copper tolerance under field conditions. Heavy metal tolerance is generally tested in hydroponic cultures, in which interfering factors can be minimised, but it is impossible to test a large number of genotypes or segregating generations using this method. Another problem in such experiments is that the conditions existing in hydroponic cultures bear little resemblance to those found in the field, so little information is obtained on the real adaptation of the varieties. The aim of the present experiments was thus to elaborate a soil-based technique suitable for determining the copper tolerance of various genotypes and allowing the simultaneous testing of a large number of genotypes under conditions approaching those found in the field. The results indicate that the copper tolerance of seedlings can be determined by growing them to an age of 2 weeks in soil containing 1000-1500 mg/kg CuSO4 × 5 H2O, since genetic differences in copper tolerance could be clearly distinguished under these conditions. The copper tolerance of plants grown in copper-containing soil exhibited a close correlation with the results obtained in physiological tests in hydroponic culture.

scholarly journals Copper tolerance of the thermoacidophilic archaeon Sulfolobus metallicus: possible role of polyphosphate metabolism

Microbiology ◽  
2006 ◽  
Vol 152 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Francisco Remonsellez ◽  
Alvaro Orell ◽  
Carlos A. Jerez
Keyword(s):  
Copper Sulfate ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Copper Tolerance ◽  
Metal Phosphate ◽  
Adaptive Responses ◽  
Inorganic Polyphosphate ◽  
Polyphosphate Metabolism ◽  
Micro Organisms ◽  
Electron Energy Loss

It has been postulated that inorganic polyphosphate (polyP) and transport of metal–phosphate complexes could participate in heavy metal tolerance in some bacteria. To study if such a system exists in archaea, the presence of polyP was determined by the electron energy loss spectroscopy (EELS) procedure and quantified by using specific enzymic methods in Sulfolobus acidocaldarius, Sulfolobus metallicus and Sulfolobus solfataricus. All three micro-organisms synthesized polyP during growth, but only S. metallicus greatly accumulated polyP granules. The differences in the capacity to accumulate polyP between these archaea may reflect adaptive responses to their natural environment. Thus, S. metallicus could grow in and tolerate up to 200 mM copper sulfate, with a concomitant decrease in its polyP levels with increasing copper concentrations. On the other hand, S. solfataricus could not grow in or tolerate more than 1–5 mM copper sulfate, most likely due to its low levels of polyP. Shifting S. metallicus cells to copper sulfate concentrations up to 100 mM led to a rapid increase in their exopolyphosphatase (PPX) activity which was concomitant in time with a decrease in their polyP levels and a stimulation of phosphate efflux. Furthermore, copper in the range of 10 μM greatly stimulated PPX activity in cell-free extracts from S. metallicus. The results strongly suggest that a metal tolerance mechanism mediated through polyP is functional in members of the genus Sulfolobus. This ability to accumulate and hydrolyse polyP may play an important role not only in the survival of these micro-organisms in sulfidic mineral environments containing high toxic metals concentrations, but also in their applications in biomining.

scholarly journals Metal Accumulation Profile of Catharanthus roseus (L.) G.Don and Celosia argentea L. with EDTA Co-Application

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 598
Author(s):  
Muneeba Qurban ◽  
Cyrus Raza Mirza ◽  
Aqib Hassan Ali Khan ◽  
Walid Khalifa ◽  
Mustapha Boukendakdji ◽  
...  
Keyword(s):  
Plant Growth ◽  
Catharanthus Roseus ◽  
Metal Uptake ◽  
Metal Accumulation ◽  
Metal Tolerance ◽  
Plant Biomass ◽  
Ethylenediaminetetraacetic Acid ◽  
Ornamental Plants ◽  
Environmental Deterioration ◽  
Celosia Argentea

The problem of metal-induced toxicity is proliferating with an increase in industrialization and urbanization. The buildup of metals results in severe environmental deterioration and harmful impacts on plant growth. In this study, we investigated the potential of two ornamental plants, Catharanthus roseus (L.) G.Don and Celosia argentea L., to tolerate and accumulate Ni, Cr, Cd, Pb, and Cu. These ornamental plants were grown in Hoagland’s nutrient solution containing metal loads (50 µM and 100 µM) alone and in combination with a synthetic chelator, ethylenediaminetetraacetic acid (EDTA) (2.5 mM). Plant growth and metal tolerance varied in both plant species for Ni, Cr, Cd, Pb, and Cu. C. roseus growth was better in treatments without EDTA, particularly in Ni, Cr, and Pb treatments, and Pb content increased in all parts of the plant. In contrast, Cd content decreased with EDTA addition. In C. argentea, the addition of EDTA resulted in improved plant biomass at both doses of Cu. In contrast, plant biomass reduced significantly in the case of Ni. In C. argentea, without EDTA, root length in Cd and Cu treatments was significantly lower than the control and other treatments. However, the addition of EDTA resulted in improved growth at both doses for Pb and Cu. Metal accumulation in C. argentea enhanced significantly with EDTA addition at both doses of Cu and Cd. Hence, it can be concluded that EDTA addition resulted in improved growth and better metal uptake than treatments without EDTA. Metal accumulation increased with EDTA addition compared to treatments without EDTA, particularly for Pb in C. roseus and Cu and Cd in C. argentea. Based on the present results, C. roseus showed a better ability to phytostabilize Cu, Cd, and Ni, while C. argentea worked better for Ni, Cd, Cu, and Pb.

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