A mechanized urease activity assay

Bzura, Justyna; Koncki, Robert

doi:10.1016/j.enzmictec.2019.01.001

Cited by 18 publications

(7 citation statements)

References 34 publications

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“…The precipitate is the urease extraction. Nessler’s reagent colorimetric method was applied to measure NH 4 + concentration ( Bzura and Koncki, 2019 ). Prior to the measurement, a calibration line was set up.…”

Section: Methodsmentioning

confidence: 99%

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

Wang

Cheng

Xue

et al. 2023

Front. Bioeng. Biotechnol.

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Inappropriate irrigation could trigger migration of heavy metals into surrounding environments, causing their accumulation and a serious threat to human central nervous system. Traditional site remediation technologies are criticized because they are time-consuming and featured with high risk of secondary pollution. In the past few years, the microbial-induced carbonate precipitation (MICP) is considered as an alternative to traditional technologies due to its easy maneuverability. The enzyme-induced carbonate precipitate (EICP) has attracted attention because bacterial cultivation is not required prior to catalyzing urea hydrolysis. This study compared the performance of lead (Pb) and copper (Cu) remediation using MICP and EICP respectively. The effect of the degree of urea hydrolysis, mass and species of carbonate precipitation, and chemical and thermodynamic properties of carbonates on the remediation efficiency was investigated. Results indicated that ammonium ion (NH4+) concentration reduced with the increase in lead ion (Pb2+) or copper ion (Cu2+) concentration, and for a given Pb2+ or Cu2+ concentration, it was much higher under MICP than EICP. Further, the remediation efficiency against Cu2+ is approximately zero, which is way below that against Pb2+ (approximately 100%). The Cu2+ toxicity denatured and even inactivated the urease, reducing the degree of urea hydrolysis and the remediation efficiency. Moreover, the reduction in the remediation efficiency against Pb2+ and Cu2+ appeared to be due to the precipitations of cotunnite and atacamite respectively. Their chemical and thermodynamic properties were not as good as calcite, cerussite, phosgenite, and malachite. The findings shed light on the underlying mechanism affecting the remediation efficiency against Pb2+ and Cu2+.

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Section: Methodsmentioning

confidence: 99%

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

Wang

Cheng

Xue

et al. 2023

Front. Bioeng. Biotechnol.

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“…After incubation at 30 °C for 30 min, the assay solution (1 mL) was heated at 80 °C for 5 min to stop the reaction. The (NH 3 + NH 4 + ) concentration was determined photometrically with the Nessler’s reagent [ 51 ].…”

Section: Methodsmentioning

confidence: 99%

Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia

Schleicher

Herdan

Fritz

et al. 2021

IJMS

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Replacement of the Lactobacillus dominated vaginal microbiome by a mixed bacterial population including Prevotella bivia is associated with bacterial vaginosis (BV). To understand the impact of P. bivia on this microbiome, its growth requirements and mode of energy production were studied. Anoxic growth with glucose depended on CO2 and resulted in succinate formation, indicating phosphoenolpyruvate carboxylation and fumarate reduction as critical steps. The reductive branch of fermentation relied on two highly active, membrane-bound enzymes, namely the quinol:fumarate reductase (QFR) and Na+-translocating NADH:quinone oxidoreductase (NQR). Both enzymes were characterized by activity measurements, in-gel fluorography, and VIS difference spectroscopy, and the Na+-dependent build-up of a transmembrane voltage was demonstrated. NQR is a potential drug target for BV treatment since it is neither found in humans nor in Lactobacillus. In P. bivia, the highly active enzymes L-asparaginase and aspartate ammonia lyase catalyze the conversion of asparagine to the electron acceptor fumarate. However, the by-product ammonium is highly toxic. It has been proposed that P. bivia depends on ammonium-utilizing Gardnerella vaginalis, another typical pathogen associated with BV, and provides key nutrients to it. The product pattern of P. bivia growing on glucose in the presence of mixed amino acids substantiates this notion.

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“…The wavelength was set at 630 nm and the zero of the spectrophotometer with blank. The concentration of unknown samples was read directly using standard (25 mg/dl) [24].…”

Section: Blood Urea Nitrogen (Bun)mentioning

confidence: 99%

Effect of ethanolic extract of rosella (Hibiscus sabdariffa L.) on vital signs, kidney, and liver safety

et al. 2022

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Summary Introduction: Rosella (Hibiscus sabdariffa L) extract is often used as immune-stimulant because it contains flavonoids, especially anthocyanin and quercetin with antioxidant activities. Objective: This study aimed to determine the safety of the rosella extract consumed in the form of capsules on the vital signs, haematologic parameters as well as kidney and liver function. Methods: This research was conducted using clinical trial pre- and post-test design in healthy participants. There were 21 healthy participants (52% male, age ranged 8–45) consuming rosella capsules for thirty days, in a dose of 500 mg extract daily. Leukocytes, lymphocytes, blood urea nitrogen (BUN), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and vital signs were consecutively evaluated on days 0, 31, and 45, respectively. The Wilcoxon and paired sample t-test were used to compare the parameters among the evaluated times. Results: The result showed that no significant difference for all parameters among the three time points (p>0.05). Conclusion: These findings suggested that the administration of ethanolic extract of rosella is potential safe and does not negatively affect the vital signs, haemoglobin, leukocytes, lymphocytes, BUN, SGOT, and SGPT.

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A mechanized urease activity assay

Cited by 18 publications

References 34 publications

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia

Effect of ethanolic extract of rosella (Hibiscus sabdariffa L.) on vital signs, kidney, and liver safety

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