Toxicity monitoring and classification of endocrine disrupting chemicals (EDCs) using recombinant bioluminescent bacteria

Chemosphere ◽  
2002 ◽  
Vol 46 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Man Bock Gu ◽  
Jiho Min ◽  
Eun Jin Kim
2021 ◽  
Author(s):  
◽  
Abbas J. Kadhem

Molecular imprinting is one of the promising techniques that have been used recently to detect trace contaminants in aqueous solution. This technique is based on the fact that the target compound is present during the polymer synthesis which gives an opportunity for the molecularly imprinted polymers (MIP) to rebind the target molecule selectivity after removal. In this thesis, it was used to detect a hormone (testosterone) in water and blood samples. The procedures are straightforward, fast, and use simple equipment. The detection of the template was carried out by using HPLC and UV-Vis. The MIP starts by preparing a template for the polymer morphology from a silica particle deposition on the glasses slides. At the beginning of this research, the silica particles were prepared by using the Stober method and then commercial silica particles were used. Bulk polymerization was used to prepare the polymer. Two types of solvent (porogen) have been applied. The composition of the prepolymerization solution was optimized. The smart sensor was used first as a self-standing film to characterize and validate. After that, the sensor was deposited on a Poly (methyl methacrylate) (PMMA) slide as a support material which made it easy to use and regenerate. The selectivity and sensitivity of the sensor to the target (testosterone) were studied. The sensor has the potential to detect testosterone not only in a water sample but also in blood samples. In addition, this sensor has the potential for integration into a microdevice for on-site and online monitoring. Such a sensor could be easily used by an inexperienced operator. In this work, the sensor was developed to detect the target with a very low concentration in blood samples. Different endocrine disrupted chemicals were used to compete for the target and to test the potential interference effect. Several human blood samples were utilized to investigate the sensor selectivity. Also, the recoverability of the sensors was studied. The detection of endocrine-disrupting chemicals by traditional methods was complicated, expensive and time-consuming. This research studied the affinity of eight EDCs to the testosterone sensor. In addition, the relation between the classification of chemicals depend on relative binding affinity (RBA) which calculated from other sources to the classification that were got from the sensor were compared to investigate any relationship between. Based on the results of the study, the chemicals were classified into 4 categories, according to their response: strong affinity (T), moderate (CHL, VIN, EST, and FLU), weak (BPA, DDE, and DCP), and inactive (DDT). Also, the percent activity showed that the selected chemicals had lower adsorption to the binding site of the sensor in comparison with testosterone. The results showed that 57 [percent] of our classification was identical with Fang classification which means that our sensor can be used as a pre method to study the affinity of EDCs binding to AR.


2002 ◽  
Vol 68 (9) ◽  
pp. 4684-4688 ◽  
Author(s):  
Yang-Hoon Kim ◽  
Jeewon Lee ◽  
Ji-Young Ahn ◽  
Man Bock Gu ◽  
Seung-Hyeon Moon

ABSTRACT Compared to yeast esterase, fungal cutinase degraded butyl benzyl phthalate (BBP) far more efficiently; i.e., almost 60% of the BBP disappeared within 7.5 h. Also, the final chemical composition significantly depended on the enzyme used. Toxicity monitoring using bioluminescent bacteria showed that butyl methyl phthalate, a major product of degradation by esterase, was an oxidative toxic hazard.


2001 ◽  
Vol 43 (2) ◽  
pp. 147-154 ◽  
Author(s):  
M. B. Gu ◽  
S. H. Choi

Recombinant bioluminescent biosensing cells were used to detect and classify toxicity caused by various chemicals in water environments. Classification of the toxicity was realized based upon the chemicals' actions of toxicity by using DNA-, oxidative- and membrane-damage sensitive strains. Tested samples contained a single chemical or mixture of chemicals in media, wastewater, or river water. Finally, it is suggested that this method for classification of toxic chemicals in wastewater or other aqueous systems may be adopted for primary screening steps of the samples and can give useful information about the samples' characteristics.


2005 ◽  
Vol 40 (4) ◽  
pp. 484-490 ◽  
Author(s):  
Keun J. Choi ◽  
Sang G. Kim ◽  
Chang W. Kim ◽  
Seung H. Kim

Abstract This study examined the effect of polyphosphate on removal of endocrine-disrupting chemicals (EDCs) such as nonylphenol and bisphenol-A by activated carbons. It was found that polyphosphate aided in the removal of nonylphenol and bisphenol- A. Polyphosphate reacted with nonylphenol, likely through dipole-dipole interaction, which then improved the nonylphenol removal. Calcium interfered with this reaction by causing competition. It was found that polyphosphate could accumulate on carbon while treating a river. The accumulated polyphosphate then aided nonylphenol removal. The extent of accumulation was dependent on the type of carbon. The accumulation occurred more extensively with the wood-based used carbon than with the coal-based used carbon due to the surface charge of the carbon. The negatively charged wood-based carbon attracted the positively charged calcium-polyphosphate complex more strongly than the uncharged coal-based carbon. The polyphosphate-coated activated carbon was also effective in nonylphenol removal. The effect was different depending on the type of carbon. Polyphosphate readily attached onto the wood-based carbon due to its high affinity for polyphosphate. The attached polyphosphate then improved the nonylphenol removal. However, the coating failed to attach polyphosphate onto the coal-based carbon. The nonylphenol removal performance of the coal-based carbon remained unchanged after the polyphosphate coating.


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