Search

To ensure clean drinking water, viable pathogens in water must be rapidly and efficiently screened. The traditional culture or spread-plate process—the conventional standard for bacterial detection—is laborious, time-consuming, and unsuitable for rapid detection. Therefore, we developed a colorimetric assay for rapid microorganism detection using a metabolism-based approach. The reaction between a viable microorganism and the combination of 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium sodium salt (WST-8) and 1-methoxy-5-methylphenazinium methyl sulfate (mPMS) results in a color change. In combination with a microplate reader, WST-8-mPMS reactivity was leveraged to develop a colorimetric assay for the rapid detection of various bacteria. The detection limit of the WST-8-mPMS assay for both gram-negative and gram-positive bacteria was evaluated. This WST-8-mPMS assay can be used to perform colorimetrical semi-quantitative detection of various bacterial strains in buffers or culture media within 1 h without incubation before the reaction. The easy-to-use, robust, rapid, and sensitive nature of this novel assay demonstrates its potential for practical and medical use for microorganism detection. [ABSTRACT FROM AUTHOR]

Corrosion is a key common science and technologies problem for oil and gas field pipelines. Microbiologically influenced corrosion(MIC) is one of the main types of corrosion in oil and gas fields, and how to control MIC is also a challenge in the oil and gas field exploitation. This paper reviews the research status, progress and the current main control methods and technologies of MIC in oil and gas fields. Corrosion microbial community, MIC mechanisms and corrosive microorganism detection and MIC control technologies are introduced, respectively. The future MIC research and corrosion control technologies are suggested as the conclusion. [ABSTRACT FROM AUTHOR]

Having an insight into graphene and graphene derivatives such as graphene oxide, reduced graphene oxide and graphene quantum dots is necessary since it can help scientists to detect possible properties and features that could be useful when using these carbon materials in preparation of a nanocomposites. In recent years, graphene and its derivatives have attracted a lot of attention and been extensively applied in biosensors due to fascinating properties, such as large surface area, optical and magnetic properties, and high elasticity for the detection of microorganisms as they can be modified with some other materials such as macromolecules, oxide metals and metals to improve the electrochemical behaviour of the biosensor. In this review paper, biosensor design strategies based on graphene and its derivatives (graphene-based nanocomposites in biosensors) are described. Then their application for the detection of microorganisms including prions, viroids, viral and bacterial cells as well as fungi, protozoa, microbial toxins and even microbial sources of antibiotics is reviewed. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Six novel fluorogenic enzyme substrates for detecting l -alanylaminopeptidase activity in microorganisms have been prepared and evaluated in Columbia agar media. The substrates are l -alanyl derivatives of 6-amino-2-hetarylquinolines and 7-amino-3-hetarylcoumarins. Both the quinoline and coumarin series of substrates produced fluorescence in the presence of Gram-negative microorganisms. In contrast, fluorescence generation in the presence of the Gram-positive microorganisms and yeasts was limited or absent. [ABSTRACT FROM AUTHOR]

The safety in agriculture, food and medicine production and processing is of grave importance to global economic and social stability. Efficient techniques for microorganism detection are essential to control health risks during product circulation. Rapid development in functional nucleic acids (FNAs) and molecular amplification technologies with improvements in the operation time, sensitivity and high throughput analysis have brought about a qualitative leap in microorganism detection. This review gives an investigative summary of many novel microorganism detection methods driven by nucleic acid-aided molecular amplification techniques (NAAMAT) in three aspects: direct to indirect methods, simple to integrated strategies, and representative applications. This paper will provide a useful reference and guide for future development of more advanced nucleic acid-aided molecular amplification techniques. • Nucleic acid aided-molecular amplification techniques (NAAMAT) are divided into 3 aspects from direct to indirect, simple to comprehensive. • The functional nucleic acids from multidimensional driven high performance amplification technology is reviewed. • A gradual in-depth participation of NAAMAT in the process of microorganism detection is analyzed comprehensively. • The application status and promising of NAAMAT in microbial detection is systematically expounded. [ABSTRACT FROM AUTHOR]

Abstract: Aptamers, single-stranded nucleic acids, provide a unique opportunity as amplifiable molecules using polymerase chain reaction (PCR) as well as recognition molecules like antibodies. We report a highly sensitive detection of Escherichia coli by taking advantage of the aptamer amplification as well as the specific binding of aptamers onto E. coli. This unique approach consists of three steps. First, the target E. coli was captured by antibody-conjugated magnetic beads. Second, the RNA aptamers were bound onto the surface of captured E. coli in a sandwich way. Finally, the heat-released aptamers were amplified by using real-time reverse-transcriptase-PCR (RT-PCR). The aptamer amplification in this approach has enabled a sensitive detection of microorganisms, such as the detection of 10 E. coli in 1ml sample. When compared to the amplification of nucleic acids extracted from the target microorganisms, this approach can not only prevent the loss of target nucleic acids during the sample preparation by obviating the necessity of cell lysis, but also provide an additional mechanism of signal amplification due to the binding of many aptamers to the surface of each E. coli. Detection of E. coli in this approach showed a wide dynamic range from 101 to 107 E. coli per ml, which can be explained by the exponential amplification of aptamers. This report has demonstrated, for the first time, the effective use of aptamer amplification in the development of sensitive microorganism detection. It is anticipated that the present approach will be easily expanded and employed in various types of microorganism detection. [Copyright &y& Elsevier]