Kinetic Analysis of Photochemical Sterilization of Thermoduric Bacterial Spores in Slurry of Semiconductor Catalyst Particles with Aeration.

Tone, Setsuji; Taya, Masahito; Katō, Susumu; Horie, Yasuhiko; Ashikaga, Yoshihiro; Joo, Hyun-Kyu

doi:10.1252/kakoronbunshu.19.1149

Cited by 18 publications

(8 citation statements)

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“…Sterilization Test. As described in our previous study (Tone et al, 1993), the sterilization experiments were conducted with a rectangular bubble-column photoreactor (40 mm in width, 40 mm in breadth, and 250 mm in height). The reactor was constructed using Plexiglas except an irradiation face made of quartz glass.…”

Section: Methodsmentioning

confidence: 99%

“…The light intensity at a given position in the reactor column, I, was measured by means of inserting a quartz glass tube with diameter of 4 mm and length of 300 mm containing the chemical actinometer (liquid height of 192 mm) in the TiO 2 suspension according to the method described previously (Tone et al, 1993). The average light intensity in the reactor column, I h obs , at a given TiO 2 concentration, was evaluated from the distribution profiles of light intensity using the equation where x ) horizontal distance (in meters) between a lamp and a given position in the reactor column and x 0 ) horizontal distance between a lamp and the irradiation face of the reactor column.…”

Section: Methodsmentioning

confidence: 99%

“…2. The concentration of oxidative radicals is constant under quasi-steady state as described by Tone et al (1993).…”

Section: Kinetic Expression Of Photocatalytic Sterilization Based On ...mentioning

confidence: 99%

“…However, there have been only a few studies on kinetics for the process of photocatalytic sterilization of viable cells in the TiO 2 system. In our previous study (Tone et al, 1993), it was reported that Bacillus stearothermophilus spores were sterilized in TiO 2 slurry under illumination using a high-pressure mercury lamp. Furthermore, the photocatalytic sterilization process of the spores was kinetically analyzed on the basis of a single-hit multitarget model, and the determined sterilization rate constant was correlated to average light intensity in the slurry, taking into account scattering and reflecting of light caused by TiO 2 particles.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Light Intensity and Titanium Dioxide Concentration on Photocatalytic Sterilization Rates of Microbial Cells

Horie

David

Taya

et al. 1996

Ind. Eng. Chem. Res.

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Photocatalytic sterilization of Escherichia coli (bacterium) or Saccharomyces serevisiae (yeast) was conducted with a rectangular bubble-column photoreactor (40 mm in width, 40 mm in breadth, and 250 mm in height) containing slurried TiO2 semiconductor particles. The profiles of cell deactivation with sterilization time could be expressed in fair agreement with experimental data, based on a series-event model and a second-order kinetics with respect to the concentrations of microbial cells and oxidative radicals generated by photoexcitation of TiO2 particles. Sterilization rate constants for the microbes were determined under various conditions of TiO2 concentrations (0−5 × 10-1 kg/m3) and average light intensities (0−223 W/m2) in the photoreactor. Linear relationships were obtained between the rate constants and average light intensity at TiO2 concentration of 1 × 10-2 kg/m3. When incident light intensity was kept constant (27 W/m2 for E. coli or 238 W/m2 for S. cerevisiae), the correlations between the rate constants and TiO2 concentration were interpreted considering a fraction of TiO2 particles adhered to the cells in slurry.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…2. The concentration of oxidative radicals is constant under quasi-steady state as described by Tone et al (1993).…”

Section: Kinetic Expression Of Photocatalytic Sterilization Based On ...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Light Intensity and Titanium Dioxide Concentration on Photocatalytic Sterilization Rates of Microbial Cells

Horie

David

Taya

et al. 1996

Ind. Eng. Chem. Res.

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“…Usage of fungicides is restricted because of their residual toxicity. Reducing environmental pollutants and microorganisms by the titanium oxide (TiO 2 ) photocatalyst is a safe method that has been developed in many places, such as in hospitals and other public places (Tone et al 1993;Watanabe 1995;Pham et al 1995;Fujishima et al 1997). In this study, we examined the possibility of using the technique in reducing numbers of bacteria and fungi pathogenic to mushrooms and those of environmental bacteria and fungi in the mushroom growing room.…”

mentioning

confidence: 99%

Disinfection of some pathogens of mushroom cultivation by photocatalytic treatment

Sawada¹,

Ohmasa

Fukuda

et al. 2005

Mycoscience

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Photocatalytic disinfection of six bacteria and fungi, including pathogens of four mushroom diseases, Trichoderma harzianum, Cladobotryum varium, Spicellum roseum, and Pseudomonas tolaasii, and Escherichia coli and Bacillus subtilis, was studied. The photocatalyst reduced the number of viable microorganisms sufficiently by near-UV irradiation. Efficiency of disinfection was increased for P. tolaasii and E. coli, but not for T. harzianum, when the superhydrophilic properties of the photocatalyst were induced by 16 h irradiation of the photocatalyst by near-UV light just before treatment of microorganisms. Efficiency of disinfection was also affected by the state of the microorganisms, temperature, and the thickness of suspensions of organisms. Tests of disinfecting ability of the photocatalyst in mushroom growing rooms indicate that it can be used effectively for reducing numbers of environmental bacteria and fungi under black light, and that it was also effective under white light.

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Deactivation kinetics of Escherichia coli cells correlated with intracellular superoxide dismutase activity in photoreaction with titanium dioxide particles

Koizumi

Yamada

Nishioka

et al. 2002

J of Chemical Tech & Biotech

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In the photoreaction of Escherichia coli IM303 (superoxide dismutase (SOD)-de®cient mutant) and MM294 (wild-type strain) with TiO 2 particles, the viability of strain IM303 decreased linearly with photoreaction time, while the time pro®le of the viability of strain MM294 exhibited a curved form. Using strain MM294 with varied initial SOD activities, the TiO 2 photoreaction tests were conducted at incident light intensities of I 0 = 4,8 and 14 W m À2, and the time pro®les of bacterial viabilities were analyzed on the basis of the series-event model. The value of n (corresponding to the step number in the series reaction kinetics described by the model) increased with an increase in initial SOD activity (A SOD,0 ), giving a mean value of A SOD,0 /n = 7.1 Â 10 À9 U cell À1 under the conditions examined. SOD activities in the cells of strain MM294 with A SOD,0 = 1.9 Â 10 À8 and 4.0 Â 10 À8 U cell À1decreased with the progress of photoreaction conducted at I 0 = 14 W m À2. The transition of intracellular SOD activities expressed was in agreement with the observed data by considering the changes in bacterial cell populations with varied SOD activities based on the proposed model.

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Kinetic Analysis of Photochemical Sterilization of Thermoduric Bacterial Spores in Slurry of Semiconductor Catalyst Particles with Aeration.

Cited by 18 publications

References 0 publications

Effects of Light Intensity and Titanium Dioxide Concentration on Photocatalytic Sterilization Rates of Microbial Cells

Effects of Light Intensity and Titanium Dioxide Concentration on Photocatalytic Sterilization Rates of Microbial Cells

Disinfection of some pathogens of mushroom cultivation by photocatalytic treatment

Deactivation kinetics of Escherichia coli cells correlated with intracellular superoxide dismutase activity in photoreaction with titanium dioxide particles

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