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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]

A series of fluorogenic heterocyclic azides were prepared and assessed as reductase substrates across a selection of Gram-negative and Gram-positive microorganisms. The majority of these azides showed similar activity profiles to nitroreductase substrates. Microorganisms that do not produce hydrogen sulfide reduced the azides, indicating reductase activity was not linked to hydrogen sulfide production. [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]

Pathogenic bacteria cause serious harm to human health, which calls for the development of advanced detection methods. Herein, we developed a novel detection platform based on fluorescence resonance energy transfer (FRET) for rapid, ultrasensitive and specific bacteria detection, where gold nanoparticles (AuNPs, acceptor) were conjugated with aptamers while upconversion nanoparticles (UCNPs, donor) were functionalized with corresponding complementary DNA (cDNA). The spectral overlap between UCNPs fluorescence emission and AuNPs absorption enables the occurrence of FRET when hybridizing the targeted aptamer and cDNA, causing upconversion fluorescence quenching. In the presence of target bacteria, the aptamers preferentially bind to bacteria forming a three-dimensional structure and thereby dissociate UCNPs-cDNA from AuNPs-aptamers, resulting in the recovery of upconversion fluorescence. Using the UCNPs based FRET aptasensor, we successfully detected Escherichia coli ATCC 8739 (as a model analyte) with a detection range of 5–10 6 cfu/mL and detection limit of 3 cfu/mL. The aptasensor was further used to detect E. coli in real food and water samples (e.g., tap/pond water, milk) within 20 min. The novel UCNPs based FRET aptasensor could be used to detect a broad range of targets from whole cells to metal ions by using different aptamer sequences, holding great potential in environmental monitoring, medical diagnostics and food safety analysis. [ABSTRACT FROM AUTHOR]

A series of carboxy-substituted 2-(nitroaryl)benzothiazole derivatives and carboxy-substituted 2-(nitroaryl)benzoxazole derivatives were prepared and evaluated as potential nitroreductase substrates for the purpose of detecting clinically important microorganisms. Several of the substrates produced highly fluorescent colonies with the majority of a panel of 10 Gram-negative bacteria and also with two of a panel of 8 Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

Highlights: [•] Proteomics in food authenticity. [•] Proteomics in food microbiology and food spoilage. [•] Proteomics in food processing. [Copyright &y& Elsevier]

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]

Abstract: The synthesis and initial evaluation of novel chromogenic substrates with potential in the detection and differentiation of cultured bacterial colonies are described. The substrates were readily hydrolysed by specific aminopeptidase activity to release the chromogen, 9-(4′-aminophenyl)-10-methylacridinium salt, which provided a clear visual indication of the presence of the corresponding bacteria. [Copyright &y& Elsevier]

Abstract: The amides 8a–e and 10a–c were prepared as chromogenic aminopeptidase substrates. A range of microorganisms were grown in the presence of these compounds and coloured colonies were produced in several cases after addition of acetic acid—thus giving potential methods for the detection of aminopeptidase activity and for microorganism identification. [Copyright &y& Elsevier]

Abstract: An eight-channel ultrasonic detecting device for microbiological quality evaluation of packed liquid foods is presented in this paper. This device makes possible a non-invasive detection of the microbial growth in liquid foods with no need to open the carton-based packages where they are contained. Thermal and humidity stabilization are required inside the measuring chamber. The changes in the liquid media produced by the microorganism growth induce variations in the ultrasonic propagation parameters giving a non-invasive evidence of the developing contamination. For that purpose, the amplitude and time of flight of an ultrasonic 800kHz tone burst travelling through an UHT milk pack are analysed. Inoculated and sterile packs were tested to evaluate the performance of this new non-invasive ultrasonic microbiological quality sensor. [Copyright &y& Elsevier]

Abstract: An eight-channel ultrasonic device was developed to detect microorganism growth in UHT milk contained in carton-like packages without opening the packs. The system analyses automatically the amplitude and the delay of an ultrasonic pulse passing through packed UHT processed milk, being the coupling between the transducers and the packs accomplished in dry conditions. Changes in these parameters produced by different microbes are detected even when other physical–chemical parameters still remain within the sterility margins. Three different strains (Bacillus cereus, Proteus vulgaris and Bacillus pumilus) were inoculated at different concentrations in UHT milk packs. Variations in the velocity and amplitude of the ultrasonic wave show the growth signature of these microorganisms. Growth detection was achieved between 7 and 48h depending on the number and type of bacteria inoculated. The experiments show that conventional analysis like pH or acidity measurements could be substituted by this non-invasive technique. [Copyright &y& Elsevier]

Abstract: A procedure for learning a probabilistic model from mass spectrometry data that accounts for domain specific noise and mitigates the complexity of Bayesian structure learning is presented. We evaluate the algorithm by applying the learned probabilistic model to microorganism detection from mass spectrometry data. [Copyright &y& Elsevier]

Abstract: We have developed a 10-plexed PCR assay coupled to a 12-plexed liquid bead array to rapidly screen environmental samples for B. anthracis, Y. pestis, F. tularensis, and B. melitensis. Highly validated species-specific primer sets were used to simultaneously amplify multiple diagnostic regions unique to each individual pathogen. Resolution of the mix of amplified products was achieved by PCR product hybridization to corresponding probe sequences, attached to unique sets of fluorescent beads. The hybridized beads were processed through a flow cytometer, which detected presence and quantity of each PCR product. The assay was optimized to allow for maximum sensitivity in a multiplexed format. A high-throughput demonstration was performed where 384 simulated environmental samples were spiked with different amounts of B. thuringensis spores and pathogen DNA. The samples were robotically processed to extract DNA and arrayed for multiplexed PCR-liquid bead detection. The assay correctly identified the presence or absence of each pathogen and collected over 3000 individual data points within a single 8-h shift for approximately $4.00 material costs per environmental sample in a 10-plexed assay. [Copyright &y& Elsevier]

Detecting cells and microorganisms in different matrices is becoming an increasingly important task in a variety of fields including bioprocess control, food technology, health care, and environmental analysis. In this review, fast on-line detection methods for this purpose are presented including different recognition and transducer strategies. [ABSTRACT FROM AUTHOR]