Effect of concentrating and exposing the bioluminescent bacteria to the non-luminescent allo-bacterial extracellular products on their luminescence (original) (raw)
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3 Bacterial bioluminescence and its application
Bioluminescent analyses are one of the most promising express methods for biologically monitoring the environment because the luminescent system is highly sensitive to even micro quantities of toxicants. Bioassays based on luminous bacteria give an integral estimation of toxicity and frequently surpass other known bioassays in speed, accuracy, sensitivity and simplicity. The enzymes of bacterial luminescent system are used in developing highly sensitive analytical methods for practical purposes. This paper considers questions about the development and use of bioluminescent bioassays, and the influence of analyzed substances on bacterial luminescence.
Frontiers in Microbiology, 2019
Bacterial-bioluminescence regulation is often associated with quorum sensing. Indeed, many studies have been made on this subject and indicate that the expression of the light-emission-involved genes is density dependent. However, most of these studies have concerned two model species, Aliivibrio fischeri and Vibrio campbellii. Very few works have been done on bioluminescence regulation for the other bacterial genera. Yet, according to the large variety of habitats of luminous marine bacteria, it would not be surprising to find different light-regulation systems. In this study, we used Photobacterium phosphoreum ANT-2200, a piezophilic bioluminescent strain isolated from Mediterranean deep-sea waters (2200-m depth). To answer the question of whether or not the bioluminescence of P. phosphoreum ANT-2200 is under quorum-sensing control, we focused on the correlation between growth and light emission through physiological, genomic and, transcriptomic approaches. Unlike A. fischeri and V. campbellii, the light of P. phosphoreum ANT-2200 immediately increases from its initial level. Interestingly, the emitted light increases at much higher rate at the low cell density than it does for higher cell-density values. The expression level of the light-emission-involved genes stays constant all along the exponential growth phase. We also showed that, even when more light is produced, when the strain is cultivated at high hydrostatic pressure, no change in the transcription level of these genes can be detected. Through different experiments and approaches, our results clearly indicate that, under the tested conditions, the genes, directly involved in the bioluminescence in P. phosphoreum ANT-2200, are not controlled at a transcriptomic level. Quite obviously, these results demonstrate that the light emission of the strain is not density dependent, which means not under quorum-sensing control. Through this study, we point out that bacterial-bioluminescence regulation should not, from now on, be always linked with the quorum-sensing control.
Isolation and Characterisation of Bioluminescent Bacteria
2016
AbstractBioluminescent bacteria are widespread in natural environment. Over the years many researcher have been studying the physiology, biochemistry & genetic control of bacterial bioluminescence. So far many problems have been experience in cultivating these bacteria in labs & maintaining their luminescence with the use of simple laboratory level microbiology practices. This project related to isolation of bioluminescent bacteria from various sample sources such as Shrimp, Squid, Octopus & fish like Raja-Rani (vernacular name) & their characterization. Bioluminescent bacteria are symbiotically associated with these organisms. These bacteria can be grown on specially designed media such as BOSS medium, NaCl complete medium. These bacteria can be used in area of environmental Microbiology using bioluminescent genes as biosensors for environmental studies. These bacteria glow in dark so they are easily identified by observing in dark..
Isolation and Characterization of Bioluminescent Bacteria
ICSESD-2017, 2017
Bacteria are the most abundant bioluminescent organisms. These luminescent bacteria are recognized to emit a blue/green light for numerous purposes and are provoked by the enzyme luciferase, regulated by the lux gene operon. Emission of light as a result of biochemical activities of living bacteria makes it possible to monitor environmental changes in ecosystems. The bioluminescent test offers a rapid, simple and sensitive method to test a wide spectrum of chemical substances and environmental samples including water, wastewater, sludge extracts, radioactive waste, hazardous radiations etc. Present study aimed at isolation and characterization of luminescent bacterial strain isolated from beaches in India. The bacterial isolates were grown at different temperatures to standardize the optimum temperature which gave maximum growth and hence luminescence. These strains were subjected to biochemical and molecular identification. Also, the bioluminescent activity was measured by calculating the luminescence using a laboratory luminometer and was expressed in RLU (Relative Luminescent Units). The isolated strain was confirmed as Vibrio harveyi and modified Nutrient Agar medium were indicated as the finest demonstrating proper bioluminescent activity most suitable for further applications.
An Objective Method to Assess Bioluminescent Properties of Selected Bacterial Strains
2007
Emission of light as a result of biochemical activities of some living bacteria Vibrio fischeri (in the past known as Photobacterium phosphoreum ) makes it possible to monitor environmental changes in ecosystems. Toxicity testing as an international stan- dard operating procedure based on the use of this method has already been accepted. The bioluminescent test offers a rapid, simple and sensitive method to test a wide spectrum of chemical substances and environmental samples including water, wastewater, sludge ex- tracts, etc. In this study, aimed at characterising and comparing bioluminescent properties, four different bacterial strains were cultivated in four different liquid mediums and tem- perature conditions. The bioluminescent intensity of bacterial suspensions was measured using a laboratory BioOrbit 1253 luminometer during bacteria culture. Based on obtained results and mathematical calculations of RLU (relative luminescent units) values strain Photobacterium phosphoreum +...
Royal Society Open Science
We present an effective dynamical model for the onset of bacterial bioluminescence, one of the most studied quorum sensing-mediated traits. Our model is built upon simple equations that describe the growth of the bacterial colony, the production and accumulation of autoinducer signal molecules, their sensing within bacterial cells, and the ensuing quorum activation mechanism that triggers bioluminescent emission. The model is directly tested to quantitatively reproduce the experimental distributions of photon emission times, previously measured for bacterial colonies of Vibrio jasicida , a luminescent bacterium belonging to the Harveyi clade, growing in a highly drying environment. A distinctive and novel feature of the proposed model is bioluminescence ‘quenching’ after a given time elapsed from activation. Using an advanced fitting procedure based on the simulated annealing algorithm, we are able to infer from the experimental observations the biochemical parameters used in the mo...
Oxygen Affinities of the Bioluminescence Systems of Various Species of Luminous Bacteria
Microbiology, 1985
O2 affinities of the bioluminescence systems have been measured in five species of luminous bacteria. Photobacterium phosphoreum He-1 a, recently isolated from a fish light-organ, showed half maximal bioluminescence at 0.01 5 ~M-O , , whereas another symbiotic strain (PJ-la) gave a 33-fold higher value. Vibrio fischeri MJ-1 gave a value of 0.60 yM-O2, and the symbiotic Photobacterium leiognathi LN-la gave half maximal emission at 0.7 pM-0,. These results indicate the importance of strain selection for sensitive O2 measurements.