scholarly journals Development of Colorimetric Whole-Cell Biosensor for Detection of Heavy Metals in Environment for Public Health

Author(s):  
Yihyang Kim ◽  
Hyeunseok Choi ◽  
Weon Ho Shin ◽  
Jong-Min Oh ◽  
Sang-Mo Koo ◽  
...  

Heavy metals cause various fetal diseases in humans. Heavy metals from factory wastewater can contaminate drinking water, fish, and crops. Inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) are commonly used to analyze heavy metal contents; however, these methods require pre-treatment processes and are expensive and complex. To overcome these limitations, three metal-sensing materials using a whole-cell biosensor in Escherichia coli (E. coli) were developed. Strains were engineered to harbor three kinds of plasmids containing the copA, zntA, and mer promoters for sensing copper, cadmium, and mercury, respectively. The luciferase (lux) gene was inserted as a reporter into the plasmid, which was later replaced with a fused protein sequence containing OmpA (1–159) and mCherry for optical detection. The constructed strains could detect mercury, cadmium, and copper at 0.1–0.75 ppm, 0.2–0.75 ppm, and 2–7.5 ppm, respectively, with linearity values of 0.99030, 0.99676, and 0.95933, respectively. The immobilization linearity value was 0.99765. Notably, these three heavy metals could be detected by visual analysis of the strains. Overall, these findings establish this novel sensor as a potential approach for heavy metal detection in biological samples and foods.

Chemosphere ◽  
2018 ◽  
Vol 200 ◽  
pp. 322-329 ◽  
Author(s):  
Zhisong Cui ◽  
Xiao Luan ◽  
Huichao Jiang ◽  
Qian Li ◽  
Guangfei Xu ◽  
...  

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 166
Author(s):  
Sergey Bazhenov ◽  
Uliana Novoyatlova ◽  
Ekaterina Scheglova ◽  
Vadim Fomin ◽  
Svetlana Khrulnova ◽  
...  

Aliivibrio fischeri LuxR and Aliivibrio logei LuxR1 and LuxR2 regulatory proteins are quorum sensing transcriptional (QS) activators, inducing promoters of luxICDABEG genes in the presence of an autoinducer (3-oxo-hexanoyl-l-homoserine lactone). In the Aliivibrio cells, luxR genes are regulated by HNS, CRP, LitR, etc. Here we investigated the role of the luxR expression level in LuxI/R QS system functionality and improved the whole-cell biosensor for autoinducer detection. Escherichia coli-based bacterial lux-biosensors were used, in which Photorhabdus luminescensluxCDABE genes were controlled by LuxR-dependent promoters and luxR, luxR1, or luxR2 regulatory genes. We varied either the dosage of the regulatory gene in the cells using additional plasmids, or the level of the regulatory gene expression using the lactose operon promoter. It was shown that an increase in expression level, as well as dosage of the regulatory gene in biosensor cells, leads to an increase in sensitivity (the threshold concentration of AI is reduced by one order of magnitude) and to a two to threefold reduction in response time. The best parameters were obtained for a biosensor with an increased dosage of luxRA. fischeri (sensitivity to 3-oxo-hexanoyl-l-homoserine lactone reached 30–100 pM).


2021 ◽  
pp. 096032712199321
Author(s):  
M Charehsaz ◽  
S Helvacıoğlu ◽  
S Çetinkaya ◽  
R Demir ◽  
O Erdem ◽  
...  

In this study, the level of arsenic (As), lead (Pb) and cadmium (Cd) and also essential elements in beer samples consumed in Turkey were investigated using the inductively coupled plasma mass spectrometry (ICP-MS) method. The heavy metal-induced non-carcinogenic and carcinogenic risks were calculated. For essential elements, the calculated estimated daily intake of iron (Fe), copper (Cu), selenium (Se) and cobalt (Co) from beer consumption were compared with their toxicity reference values. Tukey post-hoc test showed that As was found at a significantly higher level when compared to Pb. Also, a significant correlation was found between As level and alcohol by volume percent. All samples had a hazard quotient and hazard index <1, indicating no non-carcinogenic risk from exposure to single or multiple heavy metals. Some samples exceeded the threshold limit of acceptable cancer risk for As in the high beer consumer group. This assessment showed that in addition to health implications based on the alcohol content of beer, there might be a carcinogenic risk associated with the heavy metals content of these beverages.


Cosmetics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 78
Author(s):  
Claire Tubia ◽  
Alfonso Fernández-Botello ◽  
Jan Dupont ◽  
Eni Gómez ◽  
Jérôme Desroches ◽  
...  

As an external appendage, hair is exposed to multiple stresses of different origins such as particles and gases in air, or heavy metals and chemicals in water. So far, little research has addressed the impact of water pollution on hair. The present study describes a new ex vivo model that allowed us to document the adverse effects of water pollutants on the structure of hair proteins, as well as the protective potential of active cosmetic ingredients derived from a biomimetic exopolysaccharide (EPS). The impact of water pollution was evaluated on hair from a Caucasian donor repeatedly immersed in heavy metal-containing water. Heavy metal retention in and on hair was then quantified using Inductively Coupled Plasma Spectrometry (ICP/MS). The adverse effects of heavy metals on the internal structure of hair and its prevention by the EPS were assessed through measurement of keratin birefringence. Notably, the method allows the monitoring of the organization of keratin fibers and therefore the initial change on it in order to modulate the global damage in the hair. Results revealed an increasing amount of lead, cadmium and copper, following multiple exposures to polluted water. In parallel, the structure of keratin was also altered with exposures. However, heavy metal-induced keratin fiber damage could be prevented in the presence of the tested EPS, avoiding more drastic hair problems, such as lack of shine, or decrease in strength, due to damage accumulation.


2020 ◽  
Vol 27 (2) ◽  
pp. 195-210
Author(s):  
Paweł Świsłowski ◽  
Jan Kříž ◽  
Małgorzata Rajfur

AbstractIn the year 2016, passive biomonitoring studies were conducted in the forest areas of southern and north-eastern Poland: the Karkonosze Mountains (Kark), the Beskidy Mountains (Beskid), Borecka Forest (P. Bor), Knyszynska Forest (P. Kny), and Białowieza Forest (P. Bia). This study used bark from the tree, Betula pendula Roth. Samples were collected in spring (Sp), summer (Su), and autumn (Au). Concentrations of Mn, Fe, Ni, Cu, Zn, Cd, and Pb were determined for the samples using the atomic absorption spectrometry method with flame excitation (F-AAS). Based on the obtained results, the studied areas were ranked according to level of heavy-metal deposition: forests of southern Poland > forests of north-eastern Poland. Some seasonal changes in the concentrations of metals accumulated in bark were also indicated, which is directly related to their changing concentrations in the air during the calendar year, for instance, the winter heating season produces higher concentrations of heavy metals in the bark samples taken in spring. When deciding to do biomonitoring studies using bark, but also other biological materials, it is necessary to take into account the period in which the conducted research is done and the time when the samples are taken for analysis, because this will have a significant impact on the obtained results.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chang-ye Hui ◽  
Yan Guo ◽  
Jian Wu ◽  
Lisa Liu ◽  
Xue-qin Yang ◽  
...  

Cadmium (Cd) is carcinogenic to humans and can accumulate in the liver, kidneys, and bones. There is widespread presence of cadmium in the environment as a consequence of anthropogenic activities. It is important to detect cadmium in the environment to prevent further exposure to humans. Previous whole-cell biosensor designs were focused on single-sensing constructs but have had difficulty in distinguishing cadmium from other metal ions such as lead (Pb) and mercury (Hg). We developed a dual-sensing bacterial bioreporter system to detect bioavailable cadmium by employing CadC and CadR as separate metal sensory elements and eGFP and mCherry as fluorescent reporters in one genetic construct. The capability of this dual-sensing biosensor was proved to simultaneously detect bioavailable cadmium and its toxic effects using two sets of sensing systems while still maintaining similar specificity and sensitivity of respective signal-sensing biosensors. The productions of double-color fluorescence were directly proportional to the exposure concentration of cadmium, thereby serving as an effective quantitative biosensor to detect bioavailable cadmium. This novel dual-sensing biosensor was then validated to respond to Cd(II) spiked in environmental water samples. This is the first report of the development of a novel dual-sensing, whole-cell biosensor for simultaneous detection of bioavailable cadmium. The application of two biosensing modules provides versatile biosensing signals and improved performance that can make a significant impact on monitoring high concentration of bioavailable Cd(II) in environmental water to reduce human exposure to the harmful effects of cadmium.


Author(s):  
Sayyed Mohammad Ali Noori ◽  
Mohammad Hashemi ◽  
Sajjad Ghasemi

Abstract: Saffron is one of the most expensive spices in the world, and its popularity as a tasty food additive is spreading rapidly through many cultures and cuisines. Minerals and heavy metals are minor components found in saffron, which play a key role in the identification of the geographical origin, quality control, and food traceability, while they also affect human health. The chemical elements in saffron are measured using various analytical methods, such as techniques based on spectrometry or spectroscopy, including atomic emission spectrometry, atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry, and inductively coupled plasma mass spectrometry. The present study aimed to review the published articles about heavy metals and minerals in saffron across the world. To date, 64 chemical elements have been found in different types of saffron, which could be divided into three groups of macro-elements, trace elements, and heavy metals (trace elements with a lower gravity/greater than five times that of water and other inorganic sources). Furthermore, the chemical elements in the saffron samples of different countries have a wide range of concentrations. These differences may be affected by geographical condition such as physicochemical properties of the soil, weather and other environmental conditions like saffron cultivation and its genotype.


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