Radiation biophysicl study of biological molecules. Progress report, February 1, 1975--June 30, 1976. [Fast electrons, gamma and uv radiation, Escherichia coli, T1 and lambda bacteriophages]

The main objective of this work was to fully understand the bio-decontamination process in a reduced-pressure oxygen plasma. Gram-negative Escherichia coli species was chosen as the target microorganism in this test. The comparison of decontamination efficacy between plasma total and UV radiation individually under various treatment parameters and tests of DNA agarose electrophoresis were made to evaluate the inactivation effect of UV radiation. The quantity of protein leakage and the concentration of malondialdehyde (MDA), which are markers of the end products of lipid peroxidation, in bacterial suspension after treatment were determined to estimate the contribution of both charged particles and free radicals for bacterial death. In addition, a scanning electronic microscope was used to visualize the plasma effect on microorganisms. The results showed that the essential action of the oxygen plasma on Escherichia coli is believed to be attributed to the fast and intense etching on cell membrane by electrons and ions. Attacks on polyunsaturation fatty acid (PUFA) in the cell membrane by oxygen free radicals and the destruction of the DNA in the cell by UV radiation are accessorial during an effective decontamination process.

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Resistance of various shiga-toxin producing Escherichia coli (STEC) strains and serogroups to infra-red and pulsed UV radiation and effect of nalidixic acid adaptation

LWT ◽

10.1016/j.lwt.2018.11.094 ◽

2019 ◽

Vol 102 ◽

pp. 356-363 ◽

Cited By ~ 1

Author(s):

Sailaja Chintagari ◽

Raviraj Jadeja ◽

Yen-Con Hung

Keyword(s):

Escherichia Coli ◽

Nalidixic Acid ◽

Uv Radiation ◽

Shiga Toxin ◽

Acid Adaptation ◽

Infra Red

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UvrB protein of Corynebacterium pseudotuberculosis complements the phenotype of knockout Escherichia coli and recognizes DNA damage caused by UV radiation but not 8-oxoguanine in vitro

Gene ◽

10.1016/j.gene.2017.09.068 ◽

2018 ◽

Vol 639 ◽

pp. 34-43

Author(s):

Bárbara Catarina Teodoro Castro ◽

Rafael Cançado de Faria ◽

Bruna Franciele Faria ◽

Vasco Azevedo ◽

Luciana Lara dos Santos ◽

...

Keyword(s):

Escherichia Coli ◽

Dna Damage ◽

Uv Radiation ◽

Corynebacterium Pseudotuberculosis

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Solar and Temporal Effects on Escherichia coli Concentration at a Lake Michigan Swimming Beach

Applied and Environmental Microbiology ◽

10.1128/aem.70.7.4276-4285.2004 ◽

2004 ◽

Vol 70 (7) ◽

pp. 4276-4285 ◽

Cited By ~ 135

Author(s):

Richard L. Whitman ◽

Meredith B. Nevers ◽

Ginger C. Korinek ◽

Muruleedhara N. Byappanahalli

Keyword(s):

Escherichia Coli ◽

Uv Radiation ◽

Wave Height ◽

Lake Level ◽

Lake Michigan ◽

Management Strategies ◽

Day Length ◽

E Coli ◽

In Situ Experiments

ABSTRACT Studies on solar inactivation of Escherichia coli in freshwater and in situ have been limited. At 63rd St. Beach, Chicago, Ill., factors influencing the daily periodicity of culturable E. coli, particularly insolation, were examined. Water samples for E. coli analysis were collected twice daily between April and September 2000 three times a week along five transects in two depths of water. Hydrometeorological conditions were continuously logged: UV radiation, total insolation, wind speed and direction, wave height, and relative lake level. On 10 days, transects were sampled hourly from 0700 to 1500 h. The effect of sunlight on E. coli inactivation was evaluated with dark and transparent in situ mesocosms and ambient lake water. For the study, the number of E. coli samples collected (n) was 2,676. During sunny days, E. coli counts decreased exponentially with day length and exposure to insolation, but on cloudy days, E. coli inactivation was diminished; the E. coli decay rate was strongly influenced by initial concentration. In situ experiments confirmed that insolation primarily inactivated E. coli; UV radiation only marginally affected E. coli concentration. The relationship between insolation and E. coli density is complicated by relative lake level, wave height, and turbidity, all of which are often products of wind vector. Continuous importation and nighttime replenishment of E. coli were evident. These findings (i) suggest that solar inactivation is an important mechanism for natural reduction of indicator bacteria in large freshwater bodies and (ii) have implications for management strategies of nontidal waters and the use of E. coli as an indicator organism.

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