Characterization and Comparison of Metal Accumulation in Two Escherichia coli Strains Expressing Either CopA or MntA, Heavy Metal-Transporting Bacterial P-Type Adenosine Triphosphatases

2004 ◽  
Vol 117 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Nick Zagorski ◽  
David B. Wilson
AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yejin Lee ◽  
Yangwon Jeon ◽  
Guepil Jang ◽  
Youngdae Yoon

AbstractHeavy metal-responsive operons were used for the generation of Escherichia coli cell-based biosensors. The selectivity and specificity of the biosensors were determined based on the interaction between heavy metals and regulatory proteins; thereby, the modulating target selectivity of biosensors could be achieved by changing target sensing properties of regulatory proteins. The results of this study demonstrated that Pb(II)-sensing biosensors could be generated from an arsenic-responsive genetic system, which was originally used for arsenic-sensing biosensors. The amino acids around to As(III)-binding sites of ArsR were mutated and cysteine residues were relocated to modulate the metal selectivity. In addition, genes encoding metal ion-translocating P-type ATPases, such as copA and zntA, were deleted to enhance the specificity by increasing the intercellular levels of divalent metal ions. Based on the results, channel protein deleted E. coli cells harboring a pair of recombinant genes, engineered ArsR and arsAp::egfp, showed enhanced responses upon Pb exposure and could be used to quantify the amount of Pb(II) in artificially contaminated water and plants grown in media containing Pb(II). Although we focused on generating Pb(II)-specific biosensors in this study, the proposed strategy has a great potential for the generation of diverse heavy metal-sensing biosensors and risk assessment of heavy metals in environmental samples as well as in plants.


Chemosphere ◽  
2012 ◽  
Vol 88 (8) ◽  
pp. 918-924 ◽  
Author(s):  
Sandrine Sauge-Merle ◽  
Catherine Lecomte-Pradines ◽  
Patrick Carrier ◽  
Stéphan Cuiné ◽  
Michael DuBow

2019 ◽  
Vol 10 (3) ◽  
pp. 2132-2138
Author(s):  
Virsa Handayani ◽  
Rezki Amriati Syarif ◽  
Ahmad Najib ◽  
Aktsar Roskiana Ahmad ◽  
Abdullah Mahmud ◽  
...  

Mahogany (Swietenia mahagoni (L.) Jacq) is one of the plants that is often used by the community as traditional medicine. One of them is antifungal, antibacterial, antidiabetic, and eczema. This study aims to obtain standardized extracts from mahogany seeds and leaves. Standardization of purified extract of mahogany has been carried out according to the monographs of extract standardization guidelines, which include testing of specific and non-specific parameters. The results of the specific parameter testing showed that the purified extract of mahogany seeds is a thick extract, brown to reddish, smells distinctive and has a bitter taste. While the purified extract of mahogany leaves is a thick extract, greenish-brown in color, distinctive smell and has a bitter taste. The chemical content of purified extract of mahogany seeds and leaves showed the presence of flavonoids, alkaloids, terpenoids and saponins. Water-soluble essence levels in mahogany seeds and leaves was 14.84% and 10.28%. While the ethanol-soluble essence levels in mahogany seeds and leaves were 15.38% and 12.43%. Testing of non-specific parameters on mahogany seeds and leaves showed the results of drying shrinkage levels of 0.22% and 8.84%, moisture content of 2.60% and 4.04%, total ash content of 1.71% and 1.93%, levels acidic insoluble ash 0.38% and 0.32%, Total Plate Number (ALT) of mahogany seed bacteria 1x102 colonies/g, Number of mahogany mold seeds 4x10 colonies/g, heavy metal lead contamination and cadmium in mahogany seeds 0.0607µg/g and<0.003µg/g. The inhibitory diameter of each concentration of seeds against Escherichia coli, 3%, 5%, 7%, and 9%, is 12,67; 13,67; 17,67; and 19,67 mm, respectively. The inhibitory diameter of each concentration of leaves against Escherichia coli, 3%, 5%, 7%, and 9%, is 10,27; 10,90; 13,46; and 15,68 mm, respectively.


2016 ◽  
Author(s):  
Devan Fitzpatrick ◽  
◽  
Alyssa E. Shiel ◽  
Bruce McCune

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Elijah Abakpa Adegbe ◽  
Oluwaseyi Oluwabukola Babajide ◽  
Lois Riyo Maina ◽  
Shola Elijah Adeniji

Abstract Background Heavy metal accumulation in the ecosystem constitutes a potential toxic effect which is hazardous to human health. Increasing environmental pollution has necessitated the use of cattle egrets to evaluate the levels of heavy metal contamination, to establish their use in biomonitoring of heavy metals and to provide data for monitoring pollution in the environment. Results The present study assessed the utilization of Bubulcus ibis in monitoring pollution in five abattoirs, namely Agege, Bariga, Kara, Itire and Idi-Araba, all situated in Lagos State. The concentration of five (5) heavy metals, cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) was determined in the liver, muscle and feather of Bubulcus ibis using the atomic absorption spectrophotometer. The trend of metal accumulation was in the order: Zn > Cu > Pb > Cd > Ni for all the sampled tissues. The mean tissue concentrations of the metals were significantly different (p < 0.05) among the sites. The highest levels of metal concentration were reported in the liver in all the locations. Mean concentration of Cd in Kara (0.003 ± 0.00058) was significantly (p < 0.05) higher than those found at Agege (0.0013 ± 0.00058) and Idi-Araba (0.001 ± 0.001). A significant difference (p < 0.05) was also observed between the mean concentrations of Cu in Bariga (0.01 ± 0.001) and Idi-Araba (0.003 ± 0.001). Conclusion All the studied heavy metals were present in the liver, muscle and feathers of the cattle egrets. The contamination levels were ascertained from the study which indicated that cattle egrets are useful in biomonitoring studies and the generated data will serve as baseline data which could be compared with data from other locations for monitoring heavy metal pollution.


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