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.

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.

Cytoplasmic inorganic polyphosphate participates in the heavy metal tolerance of Cryptococcus humicola

2014 ◽  
Vol 59 (5) ◽  
pp. 381-389 ◽  
Author(s):  
Nadezhda Andreeva ◽  
Lubov Ryazanova ◽  
Vladimir Dmitriev ◽  
Tatiana Kulakovskaya ◽  
Igor Kulaev
Keyword(s):  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Inorganic Polyphosphate ◽  
Cryptococcus Humicola

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 Ions Stimulate Polyphosphate Degradation and Phosphate Efflux in Acidithiobacillus ferrooxidans

2004 ◽  
Vol 70 (9) ◽  
pp. 5177-5182 ◽  
Author(s):  
Sergio Alvarez ◽  
Carlos A. Jerez
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Acidithiobacillus Ferrooxidans ◽  
Genomic Sequence ◽  
Metal Tolerance ◽  
Copper Ions ◽  
Heavy Metal Tolerance ◽  
Bioinformatic Analysis ◽  
Metal Phosphate ◽  
Cell Extracts

ABSTRACT For some bacteria and algae, it has been proposed that inorganic polyphosphates and transport of metal-phosphate complexes could participate in heavy metal tolerance. To test for this possibility in Acidithiobacillus ferrooxidans, a microorganism with a high level of resistance to heavy metals, the polyphosphate levels were determined when the bacterium was grown in or shifted to the presence of a high copper concentration (100 mM). Under these conditions, cells showed a rapid decrease in polyphosphate levels with a concomitant increase in exopolyphosphatase activity and a stimulation of phosphate efflux. Copper in the range of 1 to 2 μM greatly stimulated exopolyphosphatase activity in cell extracts from A. ferrooxidans. The same was seen to a lesser extent with cadmium and zinc. Bioinformatic analysis of the available A. ferrooxidans ATCC 23270 genomic sequence did not show a putative pit gene for phosphate efflux but rather an open reading frame similar in primary and secondary structure to that of the Saccharomyces cerevisiae phosphate transporter that is functional at acidic pH (Pho84). Our results support a model for metal detoxification in which heavy metals stimulate polyphosphate hydrolysis and the metal-phosphate complexes formed are transported out of the cell as part of a possibly functional heavy metal tolerance mechanism in A. ferrooxidans.

scholarly journals Heavy Metal Tolerance Trend in Extended-Spectrum β-Lactamase Encoding Strains Recovered from Food Samples

2021 ◽  
Vol 18 (9) ◽  
pp. 4718
Author(s):  
Kashaf Junaid ◽  
Hasan Ejaz ◽  
Iram Asim ◽  
Sonia Younas ◽  
Humaira Yasmeen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Food Samples ◽  
Esbl Production ◽  
Extended Spectrum ◽  
Retail Food ◽  
Esbl Producers

This study evaluates bacteriological profiles in ready-to-eat (RTE) foods and assesses antibiotic resistance, extended-spectrum β-lactamase (ESBL) production by gram-negative bacteria, and heavy metal tolerance. In total, 436 retail food samples were collected and cultured. The isolates were screened for ESBL production and molecular detection of ESBL-encoding genes. Furthermore, all isolates were evaluated for heavy metal tolerance. From 352 culture-positive samples, 406 g-negative bacteria were identified. Raw food samples were more often contaminated than refined food (84.71% vs. 76.32%). The predominant isolates were Klebsiella pneumoniae (n = 76), Enterobacter cloacae (n = 58), and Escherichia coli (n = 56). Overall, the percentage of ESBL producers was higher in raw food samples, although higher occurrences of ESBL-producing E. coli (p = 0.01) and Pseudomonas aeruginosa (p = 0.02) were observed in processed food samples. However, the prevalence of ESBL-producing Citrobacter freundii in raw food samples was high (p = 0.03). Among the isolates, 55% were blaCTX-M, 26% were blaSHV, and 19% were blaTEM. Notably, heavy metal resistance was highly prevalent in ESBL producers. These findings demonstrate that retail food samples are exposed to contaminants including antibiotics and heavy metals, endangering consumers.

scholarly journals Effect of Lead and Copper on Photosynthetic Apparatus in Citrus (Citrus aurantium L.) Plants. The Role of Antioxidants in Oxidative Damage as a Response to Heavy Metal Stress

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 155
Author(s):  
Anastasia Giannakoula ◽  
Ioannis Therios ◽  
Christos Chatzissavvidis
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Membrane Integrity ◽  
Photosynthetic Apparatus ◽  
Heavy Metal Stress ◽  
Photosynthetic Parameters ◽  
Citrus Aurantium

Photosynthetic changes and antioxidant activity to oxidative stress were evaluated in sour orange (Citrus aurantium L.) leaves subjected to lead (Pb), copper (Cu) and also Pb + Cu toxicity treatments, in order to elucidate the mechanisms involved in heavy metal tolerance. The simultaneous effect of Pb− and Cu on growth, concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophylls, flavonoids, carotenoids, phenolics, chlorophyll fluorescence and photosynthetic parameters were examined in leaves of Citrus aurantium L. plants. Exogenous application of Pb and Cu resulted in an increase in leaf H2O2 and lipid peroxidation (MDA). Toxicity symptoms of both Pb and Cu treated plants were stunted growth and decreased pigments concentration. Furthermore, photosynthetic activity of treated plants exhibited a significant decline. The inhibition of growth in Pb and Cu-treated plants was accompanied by oxidative stress, as indicated by the enhanced lipid peroxidation and the high H2O2 concentration. Furthermore, antioxidants in citrus plants after exposure to high Pb and Cu concentrations were significantly increased compared to control and low Pb and Cu treatments. In conclusion, this study indicates that Pb and Cu promote lipid peroxidation, disrupt membrane integrity, reduces growth and photosynthesis and inhibit mineral nutrition. Considering the potential for adverse human health effects associated with high concentrations of Pb and Cu contained in edible parts of citrus plants the study signals that it is important to conduct further research into the accessibility and uptake of the tested heavy metals in the soil and whether they pose risks to humans.

Molecular mechanistic model of plant heavy metal tolerance

BioMetals ◽  
2012 ◽  
Vol 25 (3) ◽  
pp. 489-505 ◽  
Author(s):  
Ganesh Thapa ◽  
Ayan Sadhukhan ◽  
Sanjib Kumar Panda ◽  
Lingaraj Sahoo
Keyword(s):  
Heavy Metal ◽  
Metal Tolerance ◽  
Mechanistic Model ◽  
Heavy Metal Tolerance
Sign in / Sign up

Export Citation Format

Share Document