Notes: Researchers determined that the BacTiter-Glo™ Assay is a suitable method for assessing bacterial growth in water samples. (5031)

Notes: Researchers developed a high-throughput luminescence-based serum bactericidal assay using the BacTiter-Glo™ Assay. The assay is a useful tool for measuring functional antibodies elicited by Salmonella vaccines. (5030)

Notes: Biochemical oxygen demand (BOD) is useful for determining water biodegradability, and the application of this measure allows researchers to analyze the efficiency of a given water treatment process in reducing the biodegradable natural organic matter (NOM). Such analyses allow researchers to determine the amount of oxygen required for the biochemical degradation of organic material over time. BOD protocols are well established for freshwater and wastewater; however, no satisfactory standard protocols have been developed for seawater and saltwater. The authors of this study set out to develop a protocol for a reliable Mediterranean seawater analysis using an appropriate seeding method. Raw seawater was collected from the Mediterranean Sea at the desalination plant at El Prat de Llobregat (Spain). The BacTiter-Glo™ Microbial Cell Viability Assay, which uses ATP indicator as the presence of viable cells, was used to monitor inoculum activity. Assay results were measured using the GloMax® 20/20 Luminometer. The authors determined a minimum seed quantity required for reliable BOD determination. (4260)

Notes: In this study the luminescence-based BacTiter-Glo System and the GloMax 20/20 luminometer were used to detect ATP concentrations as low as 0.0001 nM in various water samples. The results correlated with those generated using traditional microbial detection methods. (4103)

Notes: In this study, the effect of solar disinfection on Shigella flexneri and Salmonella typhimurium in drinking water samples was evaluated. A variety of viability indicators were used to investigate the effectiveness of the disinfection method, including measurement of cellular ATP levels. The BacTiter-Glo Assay was used for ATP detection. (4104)

Notes: The authors of this paper review bioluminescent assay technologies, discussing HTS reporter, cell-based and luciferase biosensor assays. They divide luminescent assays into three basic categories: assays that measure ATP concentration (cell viability and kinase assays), assays that measure changes in luciferase levels (reporter assays, GPCR assays), and assays that measure changes in luciferin levels (protease [including caspase], P450 and MAO assays). (3737)

Notes: The authors of this study describe a novel bioluminescent HTS screen using the BacTiter-Glo^™ Assay to identify inhibitors of biofilm formation. They compare the BacTiter-Glo^™ Assay to conventional crystal violet staining and show that it produces higher Z´-factor values, is less messy and provides results over a greater range of bacterial OD. They used the BacTiter-Glo^™ Assay to screen more than 60,000 compounds in 384-well plates, and identified 30 compounds representing six structural classes that inhibited biofilm formation. (3735)

Notes: Photorhodopsins (PRs), retinal-binding membrane proteins that catalyze light-activated proton efflux across the cell membrane, are found in many marine bacteria. These authors screened a fosmid library of planktonic DNA, looking for PR-expressing clones. Candidate clones, identified by pigment formation on retinal-containing plates, were sequenced and subjected to transposon-mediated mutagenesis. Six genetically linked genes were identified and shown to be sufficient for the synthesis of functional PR photoprotein in E. coli. Light-induced changes in ATP levels were measured in E. coli recombinant clones expressing the PR photosystem and mutant PR- derivatives. ATP measurements performed after 5 minutes of light stimulation showed significant light-induced increases in cellular ATP levels in PR+, but not in PR- cells. The data therefore demonstrated that the E. coli clones expressing the PR genes acquired a fully functional phototrophic system that drove cellular ATP synthesis upon illumination. The BacTiter-Glo™ System was used to measure light-induced changes in ATP levels. (3581)

Notes: The BacTiter-Glo™ Microbial Cell Viability Assay was used to assess total ATP levels in Escherichia Coli strain K-12 MG165 cultures. A standard curve made from dilutions of pure rATP (Promega Cat.# P1132) was used to measure samples against E. Coli cultures treated with or without real sunlight or artificial UVA light. Cultures were added to an equal volume of BacTiter-Glo™ Reagent and luminescence was measured using a Turner BioSystems model TD-20/20 Luminometer. Data were expressed as nanograms of rATP versus fluence (UVA light dose) of cells. (3477)

Notes: Vibrio cholerae synthesizes large amounts of inorganic polyphosphate (poly-P). To investigate possible functions of this phosphate storage mechanism, these authors created a V. cholerae mutant that was unable to synthesize poly-P as it lacked the enzyme polyphosphate kinase (ppk), which catalyzes the transfer of a terminal phosphate from ATP to poly-P. The mutation had no effect on virulence. However, the mutant strain was more sensitive to environmental stress under phosphate-limiting conditions. The authors suggest that poly-P production may therefore enhance the survival of V. cholerae outside of human hosts, as the availability of such a high-energy phosphate store may enhance survival in aquatic environments where phophate concentrations may be limiting. The BacTiter-Glo™ Microbial Cell Viability Assay was used to measure ATP biosynthesis in the wildtype and ppk mutant strains under normal and phosphate-limiting conditions. (3589)