| 1. |
- Paul, Sudip Kumar, et al.
(författare)
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Higher risk of hyperglycemia with greater susceptibility in females in chronic arsenic-exposed individuals in Bangladesh
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 668, s. 1004-1012
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic (As) toxicity and diabetes mellitus (DM) are emerging public health concerns worldwide. Although exposure to high levels of As has been associated with DM, whether there is also an association between low and moderate As exposure and DM remains unclear. We explored the dose-dependent association between As exposure levels and hyperglycemia, with special consideration of the impact of demographic variables, in 641 subjects from rural Bangladesh. The total study participants were divided into three groups depending on their levels of exposure to As in drinking water (low, moderate and high exposure groups). Prevalence of hyperglycemia, including impaired glucose tolerance (IGT) and DM was significantly associated with the subjects’ drinking water arsenic levels. Almost all exposure metrics (As levels in the subjects’ drinking water, hair and nails) showed dose-dependent associations with the risk of hyperglycemia, IGT and DM. Among the variables considered, sex, age, and BMI were found to be associated with higher risk of hyperglycemia, IGT and DM. In sex-stratified analyses, As exposure showed a clearer pattern of dose-dependent risk for hyperglycemia in females than males. Finally, drinking water containing low-to-moderate levels of As (50.01–150 μg/L) was found to confer a greater risk of hyperglycemia than safe drinking water (As ≤10 μg/L). Thus the results suggested that As exposure was dose-dependently associated with hyperglycemia, especially in females. © 2019 Elsevier B.V.
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| 2. |
- Desale, Prithviraj, et al.
(författare)
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Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine
- 2014
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier. - 0147-6513 .- 1090-2414. ; 107, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (−39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04 mg of Ni(II) adsorbed on one gram of dead biomass and 196.32 mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180 min with rapid biosorption in initial 30 min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters.
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| 3. |
- Islam, Md Shofikul, et al.
(författare)
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Elevated concentrations of serum matrix metalloproteinase-2 and -9 and their associations with circulating markers of cardiovascular diseases in chronic arsenic-exposed individuals
- 2015
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiovascular diseases (CVDs) and cancers are the major causes of chronic arsenic exposure-related morbidity and mortality. Matrix metalloproteinase-2 (MMP-2) and −9 (MMP-9) are deeply involved in the pathogenesis of CVDs and cancers. This study has been designed to evaluate the interactions of arsenic exposure with serum MMP-2 and MMP-9 concentrations especially in relation to the circulating biomarkers of CVDs.Methods: A total of 373 human subjects, 265 from arsenic-endemic and 108 from non-endemic areas in Bangladesh were recruited for this study. Arsenic concentrations in the specimens were measured by inductively coupled plasma mass spectroscopy (ICP-MS) and serum MMPs were quantified by immunoassay kits.Results: Serum MMP-2 and MMP-9 concentrations in arsenic-endemic population were significantly (p < 0.001) higher than those in non-endemic population. Both MMPs showed significant positive interactions with drinking water (rs = 0.208, p < 0.001 for MMP-2; rs = 0.163, p <0.01 for MMP-9), hair (rs= 0.163, p < 0.01 for MMP-2; rs = 0.173, p < 0.01 for MMP-9) and nail (rs= 0.160, p < 0.01 for MMP-2; rs = 0.182, p < 0.001 for MMP-9) arsenic of the study subjects. MMP-2 concentrations were 1.02, 1.03 and 1.05 times, and MMP-9 concentrations were 1.03, 1.06 and 1.07 times greater for 1 unit increase in log-transformed water, hair and nail arsenic concentrations, respectively, after adjusting for covariates (age, sex, BMI, smoking habit and hypertension). Furthermore, both MMPs were increased dose-dependently when the study subjects were split into three (≤10, 10.1-50 and > 50 μg/L) groups based on the regulatory upper limit of water arsenic concentration set by WHO and Bangladesh Government. MMPs were also found to be significantly (p < 0.05) associated with each other. Finally, the concentrations of both MMPs were correlated with several circulating markers related to CVDs.Conclusions: This study showed the significant positive associations and dose–response relationships of arsenic exposure with serum MMP-2 and MMP-9 concentrations. This study also showed the interactions of MMP-2 and MMP-9 concentrations with the circulating markers of CVDs suggesting the MMP-2 and MMP-9 -mediated mechanism of arsenic-induced CVDs.
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| 4. |
- Junnarkara, Manisha V., et al.
(författare)
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Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Different Sources in Western India
- 2018
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Ingår i: Food biotechnology. - United Kingdom : Taylor & Francis. - 0890-5436 .- 1532-4249. ; 32:2, s. 112-129
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid bacteria isolated from unconventional sources are often attractive targets in the quest for obtaining better probiotics. In the present study, 16 members of the genus Lactobacillus, isolated from 3 different sources in western India, viz., plants, fermented foods and beverages, and human feces, were evaluated for their probiotic and bioactive properties. The isolates were closely related to Lactobacillus fermentum, Lactobacillus pentosus, and mainly Lactobacillus plantarum. The isolates were tolerant to bile salt, acidic pH and pancreatin, although pancreatin tolerance was generally low. Cellular extracts of several isolates displayed antioxidant activity, while cell-free supernatants displayed antibacterial activity against human pathogens. Antioxidant activity of Lactobacilli of human origin was higher than those from vegetables or fermented foods and beverages. L. plantarum AG40V prevented spoilage of fresh-cut fruits, vegetables and sprouted mung-beans. Lactobacilli from all sources displayed equal probiotic potential and those of human origin displayed superior antioxidant activity over others.
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| 5. |
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| 6. |
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| 7. |
- Nahar, Noor, et al.
(författare)
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Functional studies of AtACR2 gene putatively involved in accumulation, reduction and/or sequestration of arsenic species in plants
- 2017
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Ingår i: Biologia. - : Walter de Gruyter. - 0006-3088 .- 1336-9563. ; 72:5, s. 520-526
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Tidskriftsartikel (refereegranskat)abstract
- Food-based exposure to arsenic is a human carcinogen and can severely impact human health resulting in many cancerous diseases and various neurological and vascular disorders. This project is a part of our attempts to develop new varieties of crops for avoiding arsenic contaminated foods. For this purpose, we have previously identified four key genes, and molecular functions of two of these, AtACR2 and AtPCSl, have been studied based on both in silico and in vivo experiments. In the present study, a T-DNA tagged mutant, (SALK-143282C with mutation in AtACR2 gene) of Arabidopsis thaliana was studied for further verification of the function of AtACR2 gene. Semi-quantitative RT-PCR analyses revealed that this mutant exhibits a significantly reduced expression of the AtACR2 gene. When exposed to 100 μM of arsenate (AsV) for three weeks, the mutant plants accumulated arsenic approximately three times higher (778 μg/g d. wt.) than that observed in the control plants (235 μg/g d. wt.). In contrast, when the plants were exposed to 100 μM of arsenite (AsIII), no significant difference in arsenic accumulation was observed between the control and the mutant plants (535 μg/g d. wt. and 498 μg/g d. wt., respectively). Also, when arsenate and arsenite was measured separately either in shoots or roots, significant differences in accumulation of these substances were observed between the mutant and the control plants. These results suggest that AtACR2 gene is involved not only in accumulation of arsenic in plants, but also in conversion of arsenate to arsenite inside the plant cells. © 2017 Institute of Molecular Biology, Slovak Academy of Sciences.
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| 8. |
- Nahar, Noor, et al.
(författare)
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In silico and in vivo studies of an Arabidopsis thaliana gene, ACR2, putatively involved in arsenic accumulation in plants
- 2012
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Ingår i: Journal of Molecular Modeling. - : Springer. - 1610-2940 .- 0948-5023. ; 18:9, s. 4249-4262
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Tidskriftsartikel (refereegranskat)abstract
- Previously, our in silico analyses identified four candidate genes that might be involved in uptake and/or accumulation of arsenics in plants: arsenate reductase 2 (ACR2), phytochelatin synthase 1 (PCS1) and two multi-drug resistant proteins (MRP1 and MRP2) [Lund et al. (2010) J Biol Syst 18:223–224]. We also postulated that one of these four genes, ACR2, seems to play a central role in this process. To investigate further, we have constructed a 3D structure of the Arabidopsis thaliana ACR2 protein using the iterative implementation of the threading assembly refinement (I-TASSER) server. These analyses revealed that, for catalytic metabolism of arsenate, the arsenate binding-loop (AB-loop) and residues Phe-53, Phe-54, Cys-134, Cys-136, Cys-141, Cys-145, and Lys-135 are essential for reducing arsenate to arsenic intermediates (arsenylated enzyme-substrate intermediates) and arsenite in plants. Thus, functional predictions suggest that the ACR2 protein is involved in the conversion of arsenate to arsenite in plant cells. To validate the in silico results, we exposed a transfer-DNA (T-DNA)-tagged mutant of A. thaliana (mutation in the ACR2 gene) to various amounts of arsenic. Reverse transcriptase PCR revealed that the mutant exhibits significantly reduced expression of the ACR2 gene. Spectrophotometric analyses revealed that the amount of accumulated arsenic compounds in this mutant was approximately six times higher than that observed in control plants. The results obtained from in silico analyses are in complete agreement with those obtained in laboratory experiments.
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| 9. |
- Nahar, Noor, et al.
(författare)
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In silico and in vivo studies of molecular structures and mechanisms of AtPCS1 protein involved in binding arsenite and/or cadmium in plant cells
- 2014
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Ingår i: Journal of Molecular Modeling. - : Springer. - 1610-2940 .- 0948-5023. ; 20:3
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports a continuation of our previous research on the phytochelatin synthase1 (PCS1) gene involved in binding and sequestration of heavy metals or metalloids in plant cells. Construction of a 3D structure of the Arabidopsis thaliana PCS1 protein and prediction of gene function by employing iterative implementation of the threading assembly refinement (I-TASSER) revealed that PC ligands (3GC-gamma-glutamylcysteine) and Gln50, Pro53, Ala54, Tyr55, Cys56, Ile102, Gly161, His162, Phe163, Asp204 and Arg211 residues are essential for formation of chelating complex with cadmium (Cd²⁺) or arsenite (AsIII). This finding suggests that the PCS1 protein might be involved in the production of the enzyme phytochelatin synthase, which might in turn bind, localize, store or sequester heavy metals in plant cells. For validation of the in silico results, we included a T-DNA tagged mutant of Arabidopsis thaliana, SAIL_650_C12, (mutation in AtPCS1 gene) in our investigation. Furthermore, using reverse transcriptase PCR we confirmed that the mutant does not express the AtPCS1 gene. Mutant plants of SAIL_650_C12 were exposed to various amounts of cadmium (Cd²⁺) and arsenite (AsIII) and the accumulation of these toxic metals in the plant cells was quantified spectrophotometrically. The levels of Cd²⁺ and AsIII accumulation in the mutant were approximately 2.8 and 1.6 times higher, respectively, than that observed in the wild-type controlled plants. We confirmed that the results obtained in in silico analyses complement those obtained in in vivo experiments.
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| 10. |
- Nawani, Neelu, et al.
(författare)
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Microbial biomass for sustainable remediation of wastewater
- 2022
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Ingår i: Biomass, Biofuels, Biochemicals. - : Elsevier. - 9780323885119 ; , s. 271-292
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Bokkapitel (refereegranskat)abstract
- Microbial technologies play an extremely crucial role in wastewater treatment. In the last few decades, the focus was on wastewater treatment; however, with the consumption of already finite resources, this focus has now shifted to wastewater remediation and recycling. The latest technologies are more robust at wastewater treatment and the recovery of useful compounds from the wastewaters. This chapter compiles the latest technologies in which microbial/bacterial biomass was used for wastewater treatment and remediation. This chapter also gives a special focus on remediation of wastewaters contaminated with heavy metals, describing the basic technologies as well as smart technologies. Emphasis is given to circular bioeconomy and how it can be implemented in wastewater treatment. A circular model incorporating key areas such as point source detection of pollutants, characterization of wastewaters, choice of the remedial technology, and type of treatment is explained in the chapter.
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