scholarly journals Resistance to and Accumulation of Heavy Metals by Actinobacteria Isolated from Abandoned Mining Areas

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Soraia El Baz ◽  
Mohamed Baz ◽  
Mustapha Barakate ◽  
Lahcen Hassani ◽  
Abdelhay El Gharmali ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal Resistance ◽  
Chemical Precipitation ◽  
Metal Resistance ◽  
High Concentration ◽  
Mining Areas ◽  
Low Concentrations ◽  
High Concentrations ◽  
Mining Residues ◽  
Different Levels

Accumulation of high concentrations of heavy metals in environments can cause many human health risks and serious ecological problems. Nowadays, bioremediation using microorganisms is receiving much attention due to their good performance. The aim of this work is to investigate heavy metals resistance and bioaccumulation potential of actinobacteria strains isolated from some abandoned mining areas. Analysis of mining residues revealed that high concentration of zinc “Zn” was recorded in Sidi Bouatman, Arbar, and Bir Nhass mining residues. The highest concentration of lead “Pb” was found in Sidi Bouatman. Copper “Cu,” cadmium “Cd,” and chromium “Cr” were found with moderate and low concentrations. The resistance of 59 isolated actinobacteria to the five heavy metals was also determined. Using molecular identification 16S rRNA, these 27 isolates were found to belong toStreptomycesandAmycolatopsisgenera. The results showed different levels of heavy metal resistance; the minimum inhibitory concentration (MIC) recorded was 0.55 for Pb, 0.15 for Cr, and 0.10 mg·mL−1for both Zn and Cu. Chemical precipitation assay of heavy metals using hydrogen sulfide technic (H2S) revealed that only 27 isolates have a strong ability to accumulate Pb (up to 600 mg of Pb per g of biomass forStreptomycessp. BN3).

scholarly journals Heavy metals uptake by hyperaccumulating flora in some serpentine soils of Kosovo

2016 ◽  
Vol 18 (1) ◽  
pp. 214-222 ◽  
Keyword(s):  
Heavy Metals ◽  
Ultramafic Rocks ◽  
Metamorphic Rocks ◽  
Serpentine Soils ◽  
High Concentration ◽  
Important Indicator ◽  
Low Concentrations ◽  
Close Relationship ◽  
High Concentrations ◽  
Heavy Metals Uptake

<p>Ultramafics represent magmatic or metamorphic rocks which are characterized by high concentrations of Mg, Fe, Ni, Cr and Co and low concentrations of Ca, and K. Serpentine soils are weathered products of a range of ultramafic rocks composed of ferromagnesian silicates. The aim of this study was to determine the content of heavy metals in some of serpentine soils of Kosovo and heavy metals uptake by entire associated flora. Furthermore, another objective of this study was finding out bioavailable Ca/Mg relationship, which is very important indicator for plants&rsquo; development. The sampling was conducted in June 2014. A total of three serpentine areas have been surveyed and 7 soil samples have been taken in various depths of soil profiles. Those samples were analyzed for total Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Fe and Zn. Results showed that each site exhibited a high concentration of at least one metal. The maximum concentrations of metals in soils Dry Matter (DM) were 108.9 mg kg<sup>-1</sup> Cd, 95.8 mg kg<sup>-1</sup> Co, 1206 mg kg<sup>-1</sup> Cr, 24 mg kg<sup>-1</sup> Cu, 2570 mg kg<sup>-1</sup> Ni, 21.7 mg kg<sup>-1</sup> Pb, 39 mg kg<sup>-1</sup> Zn, and 51563 mg kg<sup>- </sup>Fe. The serpentine soils at all sites were characterized by elevated levels of heavy metals, which showed typical properties of ultramafic environments. Nickel Total at studied areas varied between 1543 and 2570 mg kg<sup>-1</sup>, while the highest Ni concentration was found in aerial part of Alyssum markgrafii (4038 mgkg<sup>-1</sup>),</p> <div> <p>Based on our findings on the field we concluded that there is a close relationship between the quantity of Ni in soil and Ni uptake in plants.</p> </div> <p>&nbsp;</p>

scholarly journals Heavy Metal Resistance Patterns of Frankia Strains

2002 ◽  
Vol 68 (2) ◽  
pp. 923-927 ◽  
Author(s):  
Joel W. Richards ◽  
Glenn D. Krumholz ◽  
Matthew S. Chval ◽  
Louis S. Tisa
Keyword(s):  
Heavy Metals ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Elemental Selenium ◽  
Inhibition Assay ◽  
Growth Inhibition Assay ◽  
Low Concentrations ◽  
Resistance Patterns ◽  
Binding Mechanisms

ABSTRACT The sensitivity of 12 Frankia strains to heavy metals was determined by a growth inhibition assay. In general, all of the strains were sensitive to low concentrations (<0.5 mM) of Ag1+, AsO2 1−, Cd2+, SbO2 1−, and Ni2+, but most of the strains were less sensitive to Pb2+ (6 to 8 mM), CrO4 2− (1.0 to 1.75 mM), AsO4 3− (>50 mM), and SeO2 2− (1.5 to 3.5 mM). While most strains were sensitive to 0.1 mM Cu2+, four strains were resistant to elevated levels of Cu2+ (2 to 5 mM and concentrations as high as 20 mM). The mechanism of SeO2 2− resistance seems to involve reduction of the selenite oxyanion to insoluble elemental selenium, whereas Pb2+ resistance and Cu2+ resistance may involve sequestration or binding mechanisms. Indications of the resistance mechanisms for the other heavy metals were not as clear.

Screening of heavy metal and antibiotic resistance among Proteus vulgaris isolates from hospital wastewater of Northern India

2021 ◽  
Vol 19 ◽  
Author(s):  
Manzar Alam ◽  
Mohd Imran ◽  
Syed Sayeed Ahmad
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Multiple Drug Resistance ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Antibiotics Resistance ◽  
Proteus Vulgaris ◽  
Resistance To Antibiotics ◽  
Transfer Frequency ◽  
Resistance Patterns

Background: Microbial resistance to antibiotics and heavy metals is a rising problem in the world today. All the Proteus vulgaris isolates showed their MIC in between 50-1600 µg/ml. Of 70% and 46% of the isolates showed their MIC at 800-1200 µg/ml against Zn2+ and Cu2+ while 80% of the isolates showed their MIC at 100-200 µg/ml against Ni2+, respectively. All Proteus vulgaris isolates also exhibited multiple resistance patterns (2-7 heavy metals) in different combination of metals. The Multi metal resistance Index (MHMR) ranges were found (0.04-0.5). Methods: A high level of antibiotics resistance was observed against Methicillin (100%) and least to Oflaxicin (6%), Gentamycine and Neomycin (10%). All Proteus vulgaris isolates also showed multiple drug resistance patterns (2-12 antibiotics) in different combination of antibiotics. The MAR index ranges were found (0.02-0.7). Of 98%, 84% and 80% of the total isolates showed urease, gelatinase and amylase activity. Results: The Proteus vulgaris isolates contained plasmid of size ranging from 42.5 to 57.0kb and molecular weight of plasmids ranged from 27.2 to 37.0 MD. Incidences of resistance transfer, 7 pairs of isolates were assessed for the transfer of the antibiotic/ heavy metal resistance markers. The higher (4.4x10-1 and 3.4x10-1) transfer frequency was observed among antibiotic and heavy metal while lower transfer frequency were (5.0x10-2 and 1.0x10-2) showed against antibiotic and heavy metal in both the medium from the entire site tested, respectively. Conclusion: Indicating the high threat of environmental pollution and appearance of heavy metal resistance which may support the enlargement of resistance to antibiotics among the pathogens.

scholarly journals Regulatory Effect of SlyA onrcsBExpression inSalmonella entericaSerovar Typhimurium

2018 ◽  
Vol 201 (4) ◽  
Author(s):  
María F. Ballesteros ◽  
Mónica F. Torrez Lamberti ◽  
Juan V. Farizano ◽  
María M. Pescaretti ◽  
Mónica A. Delgado
Keyword(s):  
Virulence Gene ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Low Concentrations ◽  
Antagonistic Behavior ◽  
Serovar Typhimurium ◽  
Direct Binding ◽  
High Concentrations ◽  
Encoding Genes ◽  
Different Levels

ABSTRACTTheSalmonella entericaserovar Typhimurium RcsCDB system regulates the synthesis of colanic acid and the flagellum as well as the expression of virulence genes. We previously demonstrated that thercsC11mutant, which constitutively activates the RcsB regulator, attenuatesSalmonellavirulence in an animal model. This attenuated phenotype was also produced by deletion of theslyAgene. In this work, we investigated if this antagonistic behavior is produced by modulating the expression of both regulator-encoding genes. We demonstrated that SlyA overproduction negatively regulatesrcsBtranscription. A bioinformatics analysis enabled us to identify putative SlyA binding sites on both promoters, PrcsDBand PrcsB, which controlrcsBtranscriptional levels. We also determined that SlyA is able to recognize and bind to these predicted sites to modulate the activity of bothrcsBpromoters. According to these results, SlyA repressesrcsBtranscription by direct binding to specific sites located on thercsBpromoters, thus accounting for the attenuated/virulence antagonistic behaviors. Moreover, we showed that the opposite effect between both regulators also physiologically affects theSalmonellamotility phenotype. In this sense, we observed that under SlyA overproduction, PrcsBis repressed, and consequently, bacterial motility is increased. On the basis of these results, we suggest that during infection, the different RcsB levels produced act as a switch between the virulent and attenuated forms ofSalmonella. Thereby, we propose that higher concentrations of RcsB tilt the balance toward the attenuated form, while absence or low concentrations resulting from SlyA overproduction tilt the balance toward the virulent form.IMPORTANCEThe antagonistic behavior of RcsB and SlyA on virulence gene expression led us to hypothesize that there is interplay between both regulators in a regulatory network and these could be considered coordinators of this process. Here, we report that the SlyA virulence factor influences motility behavior by controllingrcsBtranscription from the PrcsBpromoter. We also demonstrate that SlyA negatively affects the expression of thercsBgene by direct binding to PrcsDBand PrcsBpromoters. We suggest that different levels of RcsB act as a switch between the virulent and attenuated forms ofSalmonella, where high concentrations of the regulator tend to tilt the balance toward the attenuated form and low concentrations or its absence tilt it toward the virulent form.

scholarly journals A Review on the Resistance and Accumulation of Heavy Metals by Different Microbial Strains

2022 ◽  
Author(s):  
Madhuri Girdhar ◽  
Zeba Tabassum ◽  
Kopal Singh ◽  
Anand Mohan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Volcanic Eruptions ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Contaminated Sites ◽  
Bacillus Species ◽  
Polluted Sites ◽  
Pollution Accumulation ◽  
Microbial Strains

Heavy metals accumulated the earth crust and causes extreme pollution. Accumulation of rich concentrations of heavy metals in environments can cause various human diseases which risks health and high ecological issues. Mercury, arsenic, lead, silver, cadmium, chromium, etc. are some heavy metals harmful to organisms at even very low concentration. Heavy metal pollution is increasing day by day due to industrialization, urbanization, mining, volcanic eruptions, weathering of rocks, etc. Different microbial strains have developed very efficient and unique mechanisms for tolerating heavy metals in polluted sites with eco-friendly techniques. Heavy metals are group of metals with density more than 5 g/cm3. Microorganisms are generally present in contaminated sites of heavy metals and they develop new strategies which are metabolism dependent or independent to tackle with the adverse effects of heavy metals. Bacteria, Algae, Fungi, Cyanobacteria uses in bioremediation technique and acts a biosorbent. Removal of heavy metal from contaminated sites using microbial strains is cheaper alternative. Mostly species involved in bioremediation include Enterobacter and Pseudomonas species and some of bacillus species too in bacteria. Aspergillus and Penicillin species used in heavy metal resistance in fungi. Various species of the brown algae and Cyanobacteria shows resistance in algae.

scholarly journals Contamination of Soil and Plant By the Hazaribagh Tannery Industries

2017 ◽  
Vol 43 (2) ◽  
pp. 207-222 ◽  
Author(s):  
MN Mondol ◽  
A Asia ◽  
AS Chamon ◽  
SMA Faiz
Keyword(s):  
Heavy Metals ◽  
Metropolitan Area ◽  
Food Chain ◽  
Environmental Concern ◽  
Dry Season ◽  
High Concentration ◽  
Wet Season ◽  
Industrial Activities ◽  
Plant Samples ◽  
High Concentrations

An investigation was made at Hazaribagh Tannery area, comprising about 145 industries in Dhaka Metropolitan area. The analyses of soil and plant samples showed that heavy metals contribute significantly towards environmental contamssination resulting from industrial activities. Concentration of heavy metals (Cr, Zn, Pb, Cd, Mn, Fe and Ni) in soil and plant samples cross the MAC (Maximum allowable concentration) in both wet and dry season. In case of soil sample the highest concentration of Cr (172792 ppm) was found at main disposal point. Chromium, Zn, Pb, Cd, Mn, Fe and Ni concentrations at Hazaribagh plant samples respectively ranged from 171-1348, 247-777, 45-96, 1.66-2.17, 72-231, 354-787, and 18-38 ppm respectively in dry season and 75-1142, 209-691, 29- 84, 1.02-2.00, 66-124, 331-664, 11-37 ppm respectively in wet season. Concentration went down gradually with increasing distance from the main disposal point (spot 1). But again high concentration (150708 ppm of Cr) was noted in spot 6. Similar results were found for plant samples. High concentrations of heavy metals were found in plant samples which consequently affect food chain, which may be a major environmental concern. Asiat. Soc. Bangladesh, Sci. 43(2): 207-222, December 2017

scholarly journals Isolation and Molecular Identification of Virulence, Antimicrobial and Heavy Metal Resistance Genes in Livestock-Associated Methicillin-Resistant Staphylococcus aureus

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 79 ◽  
Author(s):  
Chumisa C. Dweba ◽  
Oliver T. Zishiri ◽  
Mohamed E. El Zowalaty
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Staphylococcus Aureus ◽  
South African ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Livestock Production ◽  
Metal Resistance ◽  
Diffusion Method ◽  
Methicillin Resistant

Staphylococcus aureus is one of the most important pathogens of humans and animals. Livestock production contributes a significant proportion to the South African Gross Domestic Product. Consequently, the aim of this study was to determine for the first time the prevalence, virulence, antibiotic and heavy metal resistance in livestock-associated S. aureus isolated from South African livestock production systems. Microbial phenotypic methods were used to detect the presence of antibiotic and heavy metal resistance. Furthermore, molecular DNA based methods were used to genetically determine virulence as well as antibiotic and heavy metal resistance determinants. Polymerase chain reaction (PCR) confirmed 217 out of 403 (53.8%) isolates to be S. aureus. Kirby-Bauer disc diffusion method was conducted to evaluate antibiotic resistance and 90.8% of S. aureus isolates were found to be resistant to at least three antibiotics, and therefore, classified as multidrug resistant. Of the antibiotics tested, 98% of the isolates demonstrated resistance towards penicillin G. High resistance was shown against different heavy metals, with 90% (196/217), 88% (192/217), 86% (188/217) and 84% (183/217) of the isolates resistant to 1500 µg/mL concentration of Cadmium (Cd), Zinc (Zn), Lead (Pb) and Copper (Cu) respectively. A total of 10 antimicrobial resistance and virulence genetic determinants were screened for all livestock associated S. aureus isolates. Methicillin-resistant S. aureus (MRSA) isolates were identified, by the presence of mecC, in 27% of the isolates with a significant relationship (p < 0.001)) with the host animal. This is the first report of mecC positive LA-MRSA in South Africa and the African continent. The gene for tetracycline resistance (tetK) was the most frequently detected of the screened genes with an overall prevalence of 35% and the highest prevalence percentage was observed for goats (56.76%) followed by avian species (chicken, duck and wild birds) (42.5%). Virulence-associated genes were observed across all animal host species. The study reports the presence of luks/pv, a gene encoding the PVL toxin previously described to be a marker for community acquired-MRSA, suggesting the crossing of species between human and livestock. The high prevalence of S. aureus from the livestock indicates a major food security and healthcare threat. This threat is further compounded by the virulence of the pathogen, which causes numerous clinical manifestations. The phenomenon of co-selection is observed in this study as isolates exhibited resistance to both antibiotics and heavy metals. Further, all the screened antibiotic and heavy metal resistance genes did not correspond with the phenotypic resistance.

scholarly journals Heavy metals in tributaries of Pampulha Reservoir, Minas Gerais

2001 ◽  
Vol 61 (3) ◽  
pp. 363-370 ◽  
Author(s):  
A. C. RIETZLER ◽  
A. L. FONSECA ◽  
G. P. LOPES
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Water Quality Management ◽  
Sampling Period ◽  
Control Site ◽  
High Concentration ◽  
Wet Season ◽  
Initial Portion ◽  
High Concentrations ◽  
Belo Horizonte

A great amount of heavy metals enter Pampulha Reservoir via it's main tributaries (Sarandi and Ressaca). Although no water quality classification has been carried out for these tributaries, the reservoir is expected to be in class 2 of the CONAMA-86 system. As part of a monitoring scheme of the Pampulha Watershed, heavy metals (Zn, Pb, Cd, Ni, Cu, Cr, Mn and Fe) were investigated in the water at a control site (considered free from direct human influence) and at potential sites of toxicity and contamination during August (dry season) and November (wet season) of 1998. The results for the first sampling period showed relatively high concentrations of zinc (0.22 mg.L<FONT FACE=Symbol>-</FONT>1) in the upper portion of the reservoir. The highest values of nickel and chromium (0.19 and 0.89 mg.L<FONT FACE=Symbol>-</FONT>1, respectively) were found in the initial portion of the Sarandi Stream, while the highest concentrations of lead (0.05 mg.L<FONT FACE=Symbol>-</FONT>1), cadmium (0.014 mg.L<FONT FACE=Symbol>-</FONT>1), manganese (0.43 mg.L<FONT FACE=Symbol>-</FONT>1) and iron (15.25 mg.L<FONT FACE=Symbol>-</FONT>1) were detected in the Ressaca Stream by the landfill dump of Belo Horizonte. A relatively high concentration of cadmium was also detected at the confluence of the two streams. During the second sampling period, there was an increase in the concentrations of zinc at all sampling sites except the control, with values varying from 0.71 mg.L<FONT FACE=Symbol>-</FONT>1 (the Sarandi Stream) to 2.50 mg.L<FONT FACE=Symbol>-</FONT>1 (the Ressaca Stream). Lead, cadmium, nickel and chromium concentrations were also higher in the Ressaca Stream, but not detected at the other sampling sites. Copper values were higher than in the first period: 0.10 mg.L<FONT FACE=Symbol>-</FONT>1 at the control up to 0.38 mg.L<FONT FACE=Symbol>-</FONT>1 at the confluence of the streams. Similar results were found for manganese and iron, with values reaching up to 19.30 and 125 mg.L<FONT FACE=Symbol>-</FONT>1, respectively. Moreover, all values recorded in the second sampling period were much higher than recommended for class 2 waters. These results emphasize the need for such monitoring in relation to better water quality management of this reservoir.

scholarly journals Molecular Characterization of Copper and Cadmium Resistance Determinants in the Biomining Thermoacidophilic ArchaeonSulfolobus metallicus

Archaea ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Alvaro Orell ◽  
Francisco Remonsellez ◽  
Rafaela Arancibia ◽  
Carlos A. Jerez
Keyword(s):  
Heavy Metals ◽  
Gene Cluster ◽  
Stress Responses ◽  
Gene Clusters ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Cadmium Resistance ◽  
Resistance Determinants ◽  
Thermophilic Archaeon ◽  
General Response

Sulfolobus metallicusis a thermoacidophilic crenarchaeon used in high-temperature bioleaching processes that is able to grow under stressing conditions such as high concentrations of heavy metals. Nevertheless, the genetic and biochemical mechanisms responsible for heavy metal resistance inS. metallicusremain uncharacterized. Proteomic analysis ofS. metallicuscells exposed to 100 mM Cu revealed that 18 out of 30 upregulated proteins are related to the production and conversion of energy, amino acids biosynthesis, and stress responses. Ten of these last proteins were also up-regulated inS. metallicustreated in the presence of 1 mM Cd suggesting that at least in part, a common general response to these two heavy metals. TheS. metallicusgenome contained two completecopgene clusters, each encoding a metallochaperone (CopM), a Cu-exporting ATPase (CopA), and a transcriptional regulator (CopT). Transcriptional expression analysis revealed thatcopMandcopAfrom eachcopgene cluster were cotranscribed and their transcript levels increased whenS. metallicuswas grown either in the presence of Cu or using chalcopyrite (CuFeS2) as oxidizable substrate. This study shows for the first time the presence of a duplicated version of thecopgene cluster inArchaeaand characterizes some of the Cu and Cd resistance determinants in a thermophilic archaeon employed for industrial biomining.

Spatial Distribution and Sources of Heavy Metal Pollution of Surface Dust in Taiyuan, China

2015 ◽  
Vol 737 ◽  
pp. 503-507
Author(s):  
Yong Zhang ◽  
Jing Xia Chen ◽  
Jun Qiu Zhang ◽  
Ying Te Wang
Keyword(s):  
Heavy Metals ◽  
Industrial Area ◽  
Shanxi Province ◽  
Surface Dust ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Development Area ◽  
High Concentrations ◽  
Functional Areas ◽  
Different Levels

The concentrations of heavy metals (Cr, Cu, Ni, Pb and Mn) were determined using flame atomic absorption spectrophotometer after digested with four acids. The samples were collected from seven kinds of different functional areas in Taiyuan, China. The concentration of the heavy metals were found in Taiyuan is higher than the soil background values in Shanxi Province, which appeared different levels of accumulation. High concentrations of Cr, Ni, Mn were found in the samples from industrial area and Cu was noted from economic development area. The correlational analysis and principle component analysis showed that the heavy metals of surface dust in Taiyuan were mainly influenced by industrial activities.

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