23 Matching Annotations
  1. Jun 2020
  2. Apr 2020
    1. . When E. coli metabolizes Collilert-18’s nutrient-indicator, MUG, the sample also fluoresces. It is reported that the method is able to detect a single viable coliform or E. coli per sample
    1. In this paper, we designed a system that could fully repress lycopene production in the absence of an inducer and produce visible lycopene within two hours of induction. We engineered Lac, Ara, and T7 systems to be up to 10 times more repressible, but these improved systems could still not fully repress lycopene. Translational modifications proved much more effective in controlling lycopene. By decreasing the strength of the ribosomal binding sites on the crtEBI genes, we enabled full repression of lycopene
    1. In the biosensor, the promoter regions of lasI, rhlI, pqsA, and ambB (QS genes) controlled the fluorescent reporter genes of Turbo YFP, mTag BFP2, mNEON Green, and E2-Orange
    1. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing

      Good comprehensive review

  3. Mar 2020
    1. In situ probes using fluorescence and infrared spectroscopy are also available on the market and have been extensively studied

      Good references for bio-monitoring in situ

      • Purely analytical methods, not biosensors

      Other points from the same paper

      • capable of monitoring the chemical properties of fermentation broths such as biomass, glucose, and protein concentration.
      • infrared spectroscopy can have problems with sensitivity, for low abundance products such as protein products or substrates such as glycerol or glucose.
      • fermentation broths are extremely complex and hence there might be interference?
  4. Jan 2020
  5. Oct 2019
    1. bioluminescence was observed during the incubation time between 90 and 150 min in the presence of a sole carbon source such as glucose, acetate, l-glutamate and BOD standard solution (GGA solution)

      So this is a limited BOD sensor for only the subset of organic compounds that E. coli can metabolize?

    1. We also show how our toolbox can be used to deploy the FBP in planta to build auto-luminescent reporters for the study of gene-expression and hormone fluxes
    1. Because growth conditions (i.e., fluid dynamics and nutrient composition) can also have a profound effect on when QS is important,(71-75) there is a need to study biofilm formation and QS of BNR bacteria under various potential operating conditions.
    1. difficult to observe in situ at the microscale, hence mechanisms and time scales relevant for bacterial spatial organization remain largely qualitative.
    1. For in situ studies of AHL-dependent signaling in complex habitats, biosensors utilizing fluorescent proteins (GFP and RFP) as reporter genes have been developed
    2. biosensors were employed to demonstrate AHL-mediated communication in swarm colonies of Serratia liquefaciens
    1. it is unclear to what extent these results are relevant in natural habitats, as the standard assays neglect the different surface chemistries, interactions with other species, and physical constraints of natural environments.
  6. Sep 2019
    1. This biosensor will help identify organic substrates that potentially support microbial growth and activity before and during nodulation
    2. Such biosensors can reveal intriguing aspects of the environment and the physiology of the free-living soil S. meliloti before and during the establishment of nodulation, and they provide a nondestructive, spatially explicit method for examining rhizosphere soil chemical composition
    1. quantifying biogeochemical fluxes resulting from these reactions remains a challenge
    2. These tools provide insights into processes such as N uptake at the scale of individual root tips, allowing observation of plant–microbe interactions on scales at which they actually occur, instead of being masked by a whole‐core average
    1. Now synthesized microbial biosensors are able to target specific toxins such as arsenic, cadmium, mercury, nitrogen, ammonium, nitrate, phosphorus and heavy metals, and respond in a variety of ways. They can be engineered to generate an electrochemical, thermal, acoustic or bioluminescent signal when encountering the designated pollutant.
  7. Aug 2019
    1. Several bacterial strains have been engineered to detect transient gene expression in the laboratory8,9,10,11 and in vivo for up to 12 d12,13

      12 days of in vivo sensing

  8. Jun 2019
    1. For example, bacteria could be engineered to seek out hazardous chemicals or heavy metals in the environment, perform cleanup and return to their origin to report on the number of hazardous sites encountered via analysis by microfluidic devices