scholarly journals Analysis of Bioavailable Toluene by Using Recombinant Luminescent Bacterial Biosensors with Different Promoters

2020 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence activities may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Analysis of Bioavailable Toluene by Using Recombinant Luminescent Bacterial Biosensors with Different Promoters

2020 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence activities may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Analysis of bioavailable toluene by using recombinant luminescent bacterial biosensors with different promoters

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

AbstractIn this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (− 14.3 to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Analysis of Bioavailable Toluene by Using Recombinant Luminescent Bacterial Biosensors with Different Promoters

2021 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Analysis of Bioavailable Toluene by Using Recombinant Luminescent Bacterial Biosensors with Different Promoters

2020 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence activities may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Analysis of Bioavailable Toluene by Using Recombinant Luminescent Bacterial Biosensors with Different Promoters

2020 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Compounds ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Measurement Range ◽  
T7 Promoter ◽  
E Coli ◽  
Low Concentrations ◽  
Relative Standard ◽  
Acceptable Deviation

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence activities may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

scholarly journals Highly Sensitive Luminescent Bioassay Using Recombinant Escherichia coli Biosensor for Rapid Detection of Low Cr(VI) Concentration in Environmental Water

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 357
Author(s):  
Guey-Horng Wang ◽  
Chiu-Yu Cheng ◽  
Teh-Hua Tsai ◽  
Pin-Kuan Chiang ◽  
Ying-Chien Chung
Keyword(s):  
Escherichia Coli ◽  
Luminescence Intensity ◽  
Limit Of Detection ◽  
Industrial Effluents ◽  
Coli Strain ◽  
Water Bodies ◽  
Recombinant Escherichia Coli ◽  
Detection Time ◽  
T7 Promoter ◽  
E Coli

In this study, we constructed a recombinant Escherichia coli strain with different promoters inserted between the chromate-sensing regulator chrB and the reporter gene luxAB to sense low hexavalent chromium (Cr(VI)) concentrations (<0.05 mg/L); subsequently, its biosensor characteristics (sensitivity, selectivity, and specificity) for measuring Cr(VI) in various water bodies were evaluated. The luminescence intensity of each biosensor depended on pH, temperature, detection time, coexisting carbon source, coexisting ion, Cr(VI) oxyanion form, Cr(VI) concentration, cell type, and type of medium. Recombinant lux-expressing E. coli with the T7 promoter (T7-lux-E. coli, limit of detection (LOD) = 0.0005 mg/L) had the highest luminescence intensity or was the most sensitive for Cr(VI) detection, followed by E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.001 mg/L) and that with the SP6 promoter (SP6-lux-E. coli, LOD = 0.005 mg/L). All biosensors could be used to determine whether the Cr(VI) standard was met in terms of water quality, even when using thawing frozen cells as biosensors after 90-day cryogenic storage. The SP6-lux-E. coli biosensor had the shortest detection time (0.5 h) and the highest adaptability to environmental interference. The T7-lux-E. coli biosensor—with the optimal LOD, a wide measurement range (0.0005–0.5 mg/L), and low deviation (−5.0–7.9%) in detecting Cr(VI) from industrial effluents, domestic effluents, and surface water—is an efficient Cr(VI) biosensor. This unprecedented study is to evaluate recombinant lux E. coli with dissimilar promoters for their possible practice in Cr(VI) measurement in water bodies, and the biosensor performance is clearly superior to that of past systems in terms of detection time, LOD, and detection deviation for real water samples.

scholarly journals Isolation of a Gene Responsible for the Oxidation oftrans-Anethole topara-Anisaldehyde by Pseudomonas putida JYR-1 and Its Expression in Escherichia coli

2012 ◽  
Vol 78 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Dongfei Han ◽  
Ji-Young Ryu ◽  
Robert A. Kanaly ◽  
Hor-Gil Hur
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Hypothetical Protein ◽  
Aldehyde Group ◽  
Agrobacterium Vitis ◽  
T7 Promoter ◽  
Content Type ◽  
E Coli ◽  
Cell Extracts ◽  
Isoeugenol Monooxygenase

ABSTRACTA plasmid, pTA163, inEscherichia colicontained an approximately 34-kb gene fragment fromPseudomonas putidaJYR-1 that included the genes responsible for the metabolism oftrans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyzetrans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter inE. colicatalyzed oxidative cleavage of a propenyl group oftrans-anethole to an aldehyde group, resulting in the production ofpara-anisaldehyde, and this gene was designatedtao(trans-anetholeoxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein ofAgrobacterium vitisS4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water intop-anisaldehyde using18O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase fromPseudomonas putidaIE27 andPseudomonas nitroreducensJin1, TAO fromP. putidaJYR-1 catalyzed isoeugenol,O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts ofE. coli(pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.

Changes in Aerobic Plate and Escherichia coli–Coliform Counts and in Populations of Inoculated Foodborne Pathogens on Inshell Walnuts during Storage

2016 ◽  
Vol 79 (7) ◽  
pp. 1143-1153 ◽  
Author(s):  
JOHN C. FRELKA ◽  
GORDON R. DAVIDSON ◽  
LINDA J. HARRIS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Relative Humidity ◽  
Low Temperature ◽  
Foodborne Pathogens ◽  
Limit Of Detection ◽  
Sampling Time ◽  
E Coli ◽  
Plate Counts ◽  
Forced Air

ABSTRACT After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P &gt; 0.05) or decreased by &lt;0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (~8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of −0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by −0.17 log CFU per nut per month and −0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent sampling time by either plating or by enrichment.

Antibacterial Effect of Monocaprylin on Escherichia coli O157:H7 in Apple Juice

2005 ◽  
Vol 68 (9) ◽  
pp. 1895-1899 ◽  
Author(s):  
MANOJ KUMAR MOHAN NAIR ◽  
HANEM ABOUELEZZ ◽  
THOMAS HOAGLAND ◽  
KUMAR VENKITANARAYANAN
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Antibacterial Effect ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Organoleptic Properties ◽  
E Coli ◽  
Low Concentrations ◽  
Storage Temperatures ◽  
Control Samples

The antibacterial effect of low concentrations of monocaprylin on Escherichia coli O157:H7 in apple juice was investigated. Apple juice alone (control) or containing 2.5 mM (0.055%) or 5 mM monocaprylin was inoculated with a five-strain mixture of E. coli O157:H7 at ~6.0 log CFU/ml. The juice samples were stored at 23 or 4°C for 14 or 21 days, respectively, and the population of E. coli O157:H7 was determined on tryptic soy agar plates supplemented with 0.6% yeast extract. At both storage temperatures, the population of E. coli O157:H7 in monocaprylin-supplemented juice samples was significantly lower (P &lt; 0.05) than that in the control samples. The concentration of monocaprylin and the storage temperature had a significant effect on the inactivation of E. coli O157:H7 in apple juice. Monocaprylin at 5 mM was significantly more effective than 2.5 mM monocaprylin for killing E. coli O157:H7 in apple juice. Inactivation of E. coli O157:H7 by monocaprylin was more pronounced in juice stored at 23°C than in the refrigerated samples. Results of this study indicated that monocaprylin is effective for killing E. coli O157:H7 in apple juice, but detailed sensory studies are needed to determine the organoleptic properties of apple juice containing monocaprylin.

scholarly journals Development of an Electrochemical Biosensor for Rapid and Effective Detection of Pathogenic Escherichia coli in Licorice Extract

2019 ◽  
Vol 9 (2) ◽  
pp. 295 ◽  
Author(s):  
Haixia Wang ◽  
Yuwen Zhao ◽  
Songtao Bie ◽  
Tongchuan Suo ◽  
Guangcheng Jia ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Electrochemical Biosensor ◽  
Linear Trend ◽  
Differential Pulse ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Colony Forming Units ◽  
Relative Standard ◽  
Licorice Extract ◽  
Pulse Voltammetry

An aptamer-based electrochemical biosensor was successfully developed and applied in the rapid detection of pathogenic Escherichia coli (E. coli) in licorice extract. The thiolated capture probes were firstly immobilized on a gold electrode, and then the biotinylated aptamer probes for E. coli were introduced by hybridization with the capture probes. Due to the stronger interaction between the aptamer and the E. coli, a part of the biotinylated aptamers will dissociate from the capture probes in the presence of E. coli. The residual biotinylated aptamer probes can quantitatively bind with streptavidin-alkaline phosphatase. Subsequently, α-naphthyl phosphate substrate was catalytically hydrolyzed to generate electrochemical response, which could be recorded by a differential pulse voltammetry. The dependence of the peak current on the logarithm of E. coli concentration in the range from 5.0 × 102 colony forming units (CFU)/mL to 5.0 × 107 CFU/mL exhibited a linear trend with a detection limit of 80 CFU/mL. The relative standard deviation of 5 successive scans was 5.3%, 4.5% and 1.1% for 5.0 × 102, 5.0 × 105 and 5.0 × 107 CFU/mL E. coli, respectively. In the detection of the licorice extract samples, the results obtained from the proposed strategy and traditional culture counting method were close to each other, but the time consumption was only ~1/30 compared with the traditional method. These results demonstrate that the designed biosensor can be potentially utilized for rapid microbial examination in traditional Chinese medicine and relevant fields.

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