Use Of Luminescent Bacteria Research Articles

Toxicity evaluation of chlorinated natural water using Photobacterium phosphoreum: Implications for ballast water management

Chlorination of ballast water could produce harmful disinfection by-products (DBPs) and total residual oxidants. The International Maritime Organization calls for toxicity testing of discharged ballast water with fish, crustacea and algae to reduce the risk, but it is difficult to evaluate the toxicity of treated ballast water in a short time. Therefore, the purpose of this study was to analyze the applicability of luminescent bacteria to the assessment of residual toxicity of chlorinated ballast water. The toxicity unit for all treated samples were higher for Photobacterium phosphoreum than for microalgae (Selenastrum capricornutum and Chlorella pyrenoidosa), after adding neutralizer, all samples showed little effect on the luminescent bacteria and microalgae. For the DBPs, except for 2,4,6-Tribromophenol, Photobacterium phosphoreum could produce more sensitive and rapid test results than other species, the results in Photobacterium phosphoreum showed that the toxicity of DBPs in order of: 2,4-Dibromophenol > 2,6-Dibromophenol > 2,4,6-Tribromophenol > Monobromoacetic acid > Dibromoacetic acid > Tribromoacetic acid, and most binary mixtures (aromatic DBPs and aliphatic DBPs) presented synergistic effects based on the CA model. The aromatic DBPs in ballast water deserve more attention. In general, for ballast water management, the use of luminescent bacteria to evaluate the toxicity of treated ballast water and DBPs is desirable, this study could provide beneficial information for enhancing ballast water management.

Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

Use of luminescent bacteria for rapid screening and characterization of short cationic antimicrobial peptides synthesized on cellulose using peptide array technology

The increasing multi-resistance of pathogenic bacteria requires the development of novel classes of antibiotics. Antimicrobial host defense peptides represent one promising class. Here we describe a protocol for screening large numbers of peptides against any microbe of interest. Peptides synthesized on a cellulose support by peptide array technology can be added to a microbe that expresses the luxCDABE (luciferase) gene cassette. Any substance that decreases the energy level within the microbe will cause a quantifiable decrease in light production. The potency of the compound, at different concentrations, is reflected by the rate of decrease in luminescence. In conjunction with peptide array technology, the screening assay is rapid and high throughput and demonstrates good correlation with conventional killing or minimal inhibitory concentration assays performed with the same peptides synthesized by standard solid-phase peptide synthesis. The protocol can be completed in 3 d.

Sensitivity and Significance of Luminescent Bacteria in Chronic Toxicity Testing Based on Growth and Bioluminescence

This study explored the use of luminescent bacteria (Vibrio fischeri) for chronic aquatic toxicity tests. The evaluated inhibition of growth to Cu2+, Cr6+, Zn2+, Hg2+, Cd2+, Pb2+, cetyltrimethylammonium bromide, 3,4-dichloroaniline, acetone, dimethylsulfoxide, ethanol, nitrobenzene, methanol, and 3,5-dichlorophenol was compared with results from another investigation, where the inhibition was determined by bioluminescence. Growth inhibition was found to indicate more reliably the presence of substances with chronic toxic properties than the loss of bioluminescence. But growth responded weaker to the majority of the analyzed toxicants than bioluminescence. This must be connected with the test parameters and the experimental conditions. But among growth experiments with freshwater bacteria species the sensitivity of the growth inhibition assay with V. fischeri is competitive when a poor medium is employed.

Use of Luminescent Bacteria for Determining the Toxicity of Plant Constituents and Complex Preparations

Use of Luminescent Bacteria for Determining the Toxicity of Plant Constituents and Complex Preparations

Bacterial luminescence: A new tool for investigating the effects of acoustic energy and cavitation

An assay utilizing luminescent bacteria, Photobacterium phosphoreum, was adapted to assess the antibacterial effects of acoustic energy. Acoustic pressures up to 67 kPa in the 100- to 800-Hz frequency range were applied to bacteria freely suspended in a liquid medium. Bacterial luminescence decreased after sonication, thus showing sensitivity to the effects of acoustic energy. This decreased luminescence was linearly related to exposure duration, appeared independent of acoustic frequency in this range, and was significantly heightened by the presence of cavitation. High-frequency components of the acoustic emission were recorded from the sonicated fluid, and it was found that the decrease in luminescence due to sonication was directly related to the logarithm of the acoustic emission. Viability studies on exposed bacteria indicated a diminution of luminescence without bacterial death. The potential use of luminescent bacteria in assessing the biological effects of acoustic energy-generating systems is discussed.

The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter

Reports investigations on the response of the bioluminescent bacteria, Photobacterium phosphoreum, to radiation and the use of the bacteria as a biological radiation dosemeter. By the latter the authors mean a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. The authors studied the effect of low LET beams of different quality on the bioluminescent survival fraction and compare the RBE values obtained with those previously published. The results show that the smallest detectable dose at present is about 1 Sv. However, there are reasons to expect an improvement in sensitivity of the system by a factor of about two in the future. It is believed that the phenomenon of bacterial luminescence loss produced by radiation will contribute to clinical radiation dosimetry and research.

Toxicity evaluation of air pollutants by use of luminescent bacteria

Cells of a species of luminescent bacteria were treated with a gas stream containing products formed by the photochemical oxidation of cis-2-butene and NO. Luminescence and viability decreased with the time of irradiation of reactants. The rate of luminescence decrease was dependent on the ratio of the initial concentrations of cis-2-butene and NO with a ratio of 2 giving the most rapid loss. Known photochemical oxidation products, ozone, NO 2, formaldehyde, acetaldehyde, and PAN were examined individually. Aldehydes did not appear to contribute to the decrease in luminescence but ozone and PAN did. Although NO 2 alone up to 0.5 ppm produced no decrease, it may contribute to the luminescence loss in the total irradiation mixture. The total oxidant concentration produced upon irradiation gave luminescence decreases which were matched by comparable concentrations of pure ozone. However, this does not imply that luminescence losses caused by photochemical oxidants are due only to ozone. A possible mechanism of the toxic effect and the interpretation of this bioassay in relation to other organisms are briefly discussed.

Evaluation of Biological Effects of Air Pollutants by Use of Luminescent Bacteria

Evaluation of Biological Effects of Air Pollutants by Use of Luminescent Bacteria