scholarly journals A Multiplex Immunosensor for Detecting Perchlorate-Reducing Bacteria for Environmental Monitoring and Planetary Exploration

2020 ◽  
Vol 11 ◽  
Author(s):  
Ignacio Gallardo-Carreño ◽  
Mercedes Moreno-Paz ◽  
Jacobo Aguirre ◽  
Yolanda Blanco ◽  
Eduardo Alonso-Pintado ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Limit Of Detection ◽  
High Arctic ◽  
Planetary Exploration ◽  
Dry Valleys ◽  
Bacterial Strains ◽  
Antibody Microarray ◽  
Chlorite Dismutase ◽  
Crude Extracts ◽  
Reducing Bacteria

Perchlorate anions are produced by chemical industries and are important contaminants in certain natural ecosystems. Perchlorate also occurs in some natural and uncontaminated environments such as the Atacama Desert, the high Arctic or the Antarctic Dry Valleys, and is especially abundant on the surface of Mars. As some bacterial strains are capable of using perchlorate as an electron acceptor under anaerobic conditions, their detection is relevant for environmental monitoring on Earth as well as for the search for life on Mars. We have developed an antibody microarray with 20 polyclonal antibodies to detect perchlorate-reducing bacteria (PRB) strains and two crucial and highly conserved enzymes involved in perchlorate respiration: perchlorate reductase and chlorite dismutase. We determined the cross-reactivity, the working concentration, and the limit of detection of each antibody individually and in a multiplex format by Fluorescent Sandwich Microarray Immunoassay. Although most of them exhibited relatively high sensitivity and specificity, we applied a deconvolution method based on graph theory to discriminate between specific signals and cross-reactions from related microorganisms. We validated the system by analyzing multiple bacterial isolates, crude extracts from contaminated reactors and salt-rich natural samples from the high Arctic. The PRB detecting chip (PRBCHIP) allowed us to detect and classify environmental isolates as well as to detect similar strains by using crude extracts obtained from 0.5 g even from soils with low organic-matter levels (<103 cells/g of soil). Our results demonstrated that PRBCHIP is a valuable tool for sensitive and reliable detection of perchlorate-reducing bacteria for research purposes, environmental monitoring and planetary exploration.

scholarly journals Characteristics of wipe sampling methods for antineoplastic drugs in North America: comparison of six providers

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Claire Chabut ◽  
Jean-François Bussières
Keyword(s):  
Environmental Monitoring ◽  
Service Provider ◽  
Sampling Methods ◽  
Service Providers ◽  
Limit Of Detection ◽  
The United States ◽  
Antineoplastic Drugs ◽  
Wipe Sampling ◽  
Pubmed Database ◽  
Google Search

Abstract Objectives Several societies have published guidelines to limit the occupational exposure of workers. Several of these guidelines recommend periodic (once or twice a year) environmental monitoring of specific sites where antineoplastic drugs are prepared and administered. However, most of the guidelines provide no guidance concerning which antineoplastic drugs should be monitored, the preferred sampling sites, appropriate test methods or limits of detection. The aim of this study was to characterize providers that quantify antineoplastic drug measured on surfaces. Methods This was a cross-sectional descriptive study. To identify service providers offering environmental monitoring tests, we searched the PubMed database and used the Google search engine. We contacted each service provider by email between June 3rd and June 15th, 2020. We specified the objective of our study and described the information needed and the variables of interest with standardized questions. Additional questions were sent by emails or via teleconferences. No statistical analyses were performed. Results We identified six providers offering services to Canadian hospitals, either based in Canada or in the United States. Five of these providers were private companies and one was a public organization. Each service provider was able to measure trace contamination of 3–17 antineoplastic drugs. Five of the providers quantified drugs using ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MSMS), which allowed for lower LODs. The sixth provider offered quantification by immunoassay, which has higher LODs, but offers near real-time results; the surface area to be sampled with this method was also smaller than with UPLC-MSMS. The services offered varied among the service providers. The information about LODs supplied by each provider was often insufficient and the units were not standardized. A cost per drug quantified could not be obtained, because of variability in the scenarios involved (e.g. drug selection to be quantified, number of samples, nondisclosure of ancillary costs). Four of the six service providers were unable to report LOQ values. Conclusions Few data are available from Canadian service providers concerning the characteristics of wipe sampling methods for antineoplastics. This study identified six north-American providers. Their characteristics were very heterogeneous. Criteria to consider when choosing a provider include the validation of their analytical method, a low limit of detection, the choice of drugs to be quantified and the sites to be sampled, obtaining details about the method and understanding its limits, and price. This should be part of a structured multidisciplinary approach in each center.

scholarly journals Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’

2021 ◽  
Vol 1 (1) ◽  
pp. 11-23
Author(s):  
Arjun Bhusal ◽  
Peter M. Muriana
Keyword(s):  
Nitrate Reduction ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Test Tube ◽  
Screening Assay ◽  
Isolation And Characterization ◽  
The Us ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.

scholarly journals Antibody Microarray Immunoassay for Simultaneous Quantification of Multiple Mycotoxins in Corn Samples

Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 415 ◽  
Author(s):  
Xian Zhang ◽  
Zuohuan Wang ◽  
Yun Fang ◽  
Renjie Sun ◽  
Tong Cao ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Aflatoxin B1 ◽  
Goodness Of Fit ◽  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Fumonisin B1 ◽  
Quantitative Detection ◽  
Antibody Microarray ◽  
Test Kit ◽  
Microarray Immunoassay

We developed and tested a prototype of an antibody microarray immunoassay for simultaneous quantitative detection of four typical mycotoxins (aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1) in corn samples. The test kit consisted of a nitrocellulose membrane layered with immobilized monoclonal antibodies against mycotoxins. During the assay, the mycotoxin-protein conjugates were biotinylated. The signal detection was enhanced by a combination of the biotin-streptavidin system and enhanced chemiluminescence (ECL). This improved the sensitivity of the assay. Under the optimized conditions, four calibration curves with goodness of fit (R2 > 0.98) were plotted. The results showed that the detection limits for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 were 0.21, 0.19, 0.09, and 0.24 ng/mL, with detection ranges of 0.47–55.69, 0.48–127.11, 0.22–31.36, and 0.56–92.57 ng/mL, respectively. The limit of detection (LOD) of this antibody microarray for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 in corn was 5.25, 4.75, 2.25, and 6 μg/kg, respectively. The recovery rates from the spiked samples were between 79.2% and 113.4%, with coefficient of variation <10%. The results of the analysis of commercial samples for mycotoxins using this new assay and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) were comparable and in good agreement. This assay could also be modified for the simultaneous detection of other multiple mycotoxins, as well as low-weight analytes, hazardous to human health.

scholarly journals Direct and Fe(II)-Mediated Reduction of Technetium by Fe(III)-Reducing Bacteria

2000 ◽  
Vol 66 (9) ◽  
pp. 3743-3749 ◽  
Author(s):  
J. R. Lloyd ◽  
V. A. Sole ◽  
C. V. G. Van Praagh ◽  
D. R. Lovley
Keyword(s):  
Dna Analysis ◽  
Limit Of Detection ◽  
Geobacter Sulfurreducens ◽  
Biogenic Magnetite ◽  
Enzymatic Reduction ◽  
Rapid Formation ◽  
Oxidation Of Hydrogen ◽  
Direct Cell ◽  
Reducing Bacteria ◽  
Mediated Reduction

ABSTRACT The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of Tc(VII) to Tc(IV), leading to the precipitation of TcO2 at the periphery of the cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently as an electron donor for direct cell-mediated reduction of technetium, supported the reduction of Fe(III), and the Fe(II) formed was able to transfer electrons abiotically to Tc(VII). Tc(VII) reduction was comparatively inefficient via this indirect mechanism when soluble Fe(III) citrate was supplied to the cultures but was enhanced in the presence of solid Fe(III) oxide. The rate of Tc(VII) reduction was optimal, however, when Fe(III) oxide reduction was stimulated by the addition of the humic analog and electron shuttle anthaquinone-2,6-disulfonate, leading to the rapid formation of the Fe(II)-bearing mineral magnetite. Under these conditions, Tc(VII) was reduced and precipitated abiotically on the nanocrystals of biogenic magnetite as TcO2 and was removed from solution to concentrations below the limit of detection by scintillation counting. Cultures of Fe(III)-reducing bacteria enriched from radionuclide-contaminated sediment using Fe(III) oxide as an electron acceptor in the presence of 25 μM Tc(VII) contained a singleGeobacter sp. detected by 16S ribosomal DNA analysis and were also able to reduce and precipitate the radionuclide via biogenic magnetite. Fe(III) reduction was stimulated in aquifer material, resulting in the formation of Fe(II)-containing minerals that were able to reduce and precipitate Tc(VII). These results suggest that Fe(III)-reducing bacteria may play an important role in immobilizing technetium in sediments via direct and indirect mechanisms.

Arsenic-hypertolerant and arsenic-reducing bacteria isolated from wells in Tucumán, Argentina

2018 ◽  
Vol 64 (11) ◽  
pp. 876-886 ◽  
Author(s):  
Daniela Maizel ◽  
Pilar Balverdi ◽  
Barry Rosen ◽  
Adriana M. Sales ◽  
Marcela A. Ferrero
Keyword(s):  
Inductively Coupled Plasma ◽  
High Performance ◽  
World Health ◽  
Bacterial Strains ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Major Anions ◽  
Health Organization ◽  
Reducing Bacteria ◽  
The Village

Arsenic-hypertolerant bacteria were isolated from arsenic-contaminated well water from the village of Los Pereyra in Tucumán province, Argentina. Microorganisms that biotransform arsenic are a major factor in arsenic mobilization in contaminated aquifers. Groundwater analyses showed a level of arsenic contamination (mean concentration of 978 μg·L−1) that exceeds the safe drinking water limit of 10 μg·L−1recommended by the World Health Organization and the Argentine Food Code. There was considerable spatial variability in the concentration of arsenic in each of the wells analyzed and in the distribution of the major anions HCO3–, SO42–, and Cl–. Eighteen bacterial strains were characterized. Six strains belonging to the Actinobacteria phylum were able to grow in media with 20 mmol·L–1As(III) or 200 mmol·L–1As(V) and were also highly resistant to Cr, Cd, and Cu. Their ability to biotransform arsenic was examined by speciation of the products by high-performance liquid chromatography inductively coupled plasma mass spectrometry. In addition, two strains, Brevibacterium sp. strain AE038-4 and Microbacterium sp. strain AE038-20, were capable of aerobic arsenate reduction, which suggests that these strains could increase the mobility of arsenic by formation of more mobile As(III).

scholarly journals A 200-Antibody Microarray Biochip for Environmental Monitoring: Searching for Universal Microbial Biomarkers through Immunoprofiling

2008 ◽  
Vol 80 (21) ◽  
pp. 7970-7979 ◽  
Author(s):  
Luis A. Rivas ◽  
Miriam García-Villadangos ◽  
Mercedes Moreno-Paz ◽  
Patricia Cruz-Gil ◽  
Javier Gómez-Elvira ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Antibody Microarray ◽  
Microbial Biomarkers

scholarly journals Antibacterial and Antifungal Screening of Centaurium Pulchellum Crude Extracts and Main Secoiridoid Compounds

2010 ◽  
Vol 5 (10) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Branislav Šiler ◽  
Danijela Mišić ◽  
Jasmina Nestorović ◽  
Tijana Banjanac ◽  
Jasmina Glamočlija ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Fungal Species ◽  
Bacterial Strains ◽  
Methanol Extracts ◽  
Aerial Parts ◽  
Crude Extracts ◽  
Secoiridoid Glycosides ◽  
Antibacterial And Antifungal

The main principles of C. pulchellum (Sw.) Druce, secoiridoid glycosides, have been studied as potent bioactive compounds. Here we scored their content in extracts of ten populations of this species. Antibacterial and antifungal assays of the extracts and pure secoiridoid glycosides were performed against eight bacterial strains and five fungal species. Methanol extracts from both aerial parts and roots exhibited excellent antibacterial (0.05-0.2 mg mL−1) and very good antifungal (0.1-2 mg mL−1) activity. Pure secoiridoid glycosides isolated from these extracts demonstrated very strong antibacterial (0.01-0.04 mg mL−1) and especially antifungal (0.001-0.1 mg mL−1) activity.

scholarly journals Biocleaning to Remove Graffiti: A Real Possibility? Advances towards a Complete Protocol of Action

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 104 ◽  
Author(s):  
Patricia Sanmartín ◽  
Pilar Bosch-Roig
Keyword(s):  
Target Surface ◽  
Bacterial Strains ◽  
Simple Task ◽  
Anaerobic Microorganisms ◽  
Infrared Measurements ◽  
Complex Chemical Composition ◽  
Cleaning Procedures ◽  
Methodological Aspects ◽  
Reducing Bacteria

The first academic studies on the use of microorganisms in cleaning procedures appeared in the late 1980s/early 1990s. In the past thirty years, most of such studies have addressed the removal of nitrate and sulphate salts and organic matter from surfaces by using non-pathogenic anaerobic microorganisms, mainly sulphate-reducing bacteria. The successful use of microbes in the removal of graffiti paint remains, however, a work in progress. Biocleaning surfaces to remove graffiti is not a simple task, because of the complex chemical composition of graffiti paints. This study looks at ways of improving the bioremoval of graffiti and presents the latest findings regarding different methodological aspects of cleaning natural and man-made stone. Granite and concrete substrates were coated with silver and black graffiti spray paints for comparison of the efficacy of the biocleaning method on these different materials. Visual and microscopic examination along with colour and infrared measurements made after application of the bacterial strains tested (previously shown to be suitable candidates for bioremoval of graffiti) revealed remarkably successful results. The findings presented thus represent progress in the development of a biocleaning protocol applicable to the in-situ removal of graffiti. Important improvements have been made regarding the time of treatment, which has been reduced by up to 20 days, and the use of a culture medium enriched with powdered graffiti, which facilitates and accelerates the adaptation of the microorganisms to the target surface.

scholarly journals Investigation of Antimicrobial Properties of Doscorea pentaphylla from Mid Western Ghats, India

1970 ◽  
Vol 8 (8) ◽  
pp. 91-96 ◽  
Author(s):  
G Prakash ◽  
BB Hosetti
Keyword(s):  
Western Ghats ◽  
Fungal Infections ◽  
Petroleum Ether Extract ◽  
Pathogenic Fungi ◽  
Antibacterial Drug ◽  
Bacterial Strains ◽  
Traditional Use ◽  
Standard Drug ◽  
Clinical Strains ◽  
Crude Extracts

Antibacterial and antifungal activity of crude extracts of medicinally important and traditionally used yam plant Dioscorea pentaphylla from mid Western Ghats was evaluated against 27 bacterial and 5 fungal clinical strains collected of the patients from infectious sources. The clinical strains belonging to their respective species showed concentration dependent susceptibility towards crude petroleum ether extract, chloroform extract and methanol extract at 100ìg/100ìL. All the extracts exhibited predominant antibacterial activity against S. aureus (ATCC-20852), P. aeruginosa (ATCC-29737) and K. pneumoniae (MTCC-618) respectively. and five clinically isolated pathogenic fungi, T. rubrum, M. gypseum, T. tonsurans, M. audouini, and C. albicans with antibacterial drug Ciprofloxacin and antifungal drug Fluconozole (50ìg/100ìL) as the standard drug. Out of three extracts, ethanol extracts possessed better minimum inhibition concentration against all the bacterial strains. All the three extracts showed significant result against all the five fungal pathogen strains. The results are promising and supported the traditional use of D. Pentaphylla for the treatment of bacterial and fungal infections. Keywords : Antifungal; Antibacterial; Crude extracts Dioscorea pentaphylla; MIC and Traditional medicine. DOI: 10.3126/sw.v8i8.3857 Scientific World Vol.8(8) 2010 pp.91-96

scholarly journals Isolation and Characterization of Chromate Resistant and Reducing Bacteria from Tannery Effluent of Chittagong, Bangladesh

1970 ◽  
Vol 17 ◽  
pp. 71-76
Author(s):  
M Fakruddin ◽  
Reaz Mohammad Mazumder ◽  
Towhida Khanom Tania ◽  
Saiful Islam ◽  
Meher Nigad Nipa ◽  
...  
Keyword(s):  
Atomic Absorption Spectrophotometry ◽  
Luria Bertani ◽  
Tannery Effluent ◽  
Bacterial Strains ◽  
E Coli ◽  
Absorption Spectrophotometry ◽  
Isolation And Characterization ◽  
Enzymatic Reduction ◽  
Reducing Bacteria

Context: Waste water containing Chromium (Cr6+) is by far the most important environmental challenge being faced. Objectives: The present study was planned on the isolation and characterization of chromate resistant and reducing bacterial strains in order to use them for detoxification of chromate.Materials and Methods: Water samples were collected to isolate microorganisms from tannery effluent of Baluchara, Chittagong and inoculated into Luria-Bertani medium with added Cr6+ as K2Cr2O7. The organisms have been identified and studied for Cr6+ reduction-ability in growth dependent manner.Results: A total of 35 isolates have been selected as potential organism belonging to the species of Moraxella (14.3%), Bacillus (11.43%), Streptococcus (25.72%), Staphylococcus (5.7%), Salmonella (12.3%), E. coli (13.3%), Enterobacter (11.3%), Hafnia alvei (2.45%) and Alcaligenes (3.5%). The selected isolates were able to tolerate at least 500 mg/l of Cr6+. The total Cr6+ concentration of the effluent sample analysed was found to be about 23.73 mg/l as determined by Atomic Absorption Spectrophotometry. Two of the isolates reduced 38% and 32% of Cr6+ added to the medium. Another 7 isolates showed Cr6+; reducing capability ranging from 18 to 22%.Conclusion: As the isolates have turned out to successfully reduce Cr6+ in this study, these can be used for the development of bioremediation process. Key words: Enzymatic reduction; Bioremediation; Chromium; Ecotoxicity; Tannery.DOI: 10.3329/jbs.v17i0.7104J. bio-sci. 17: 71-76, 2009

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