Ultrasonic Radiation and Yeast Cells

Beckwith, T. D.; Olson, A. R.

doi:10.3181/00379727-29-5887

Cited by 17 publications

(6 citation statements)

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“…Effect of type of container. Some investigators (Williams and Gaines, 1930;Chambers and Flosdorf, 1936) have used glass containers for the material being treated with ultrasonic energy, whereas others have used cellophane-bottomed containers (Beckwith and Weaver, 1936; Beckwith and Olson, 1931;Haas, 1943). In our experiments (figure 1) the mortality of K. pneumoniae when 10 ml of a 1:10 dilution in broth of a 17-hour culture was treated with ultrasonic waves in a cellophane-bottomed container was higher than when an Erlenmeyer flask was used.…”

Section: Resultsmentioning

confidence: 99%

The Effect of Ultrasonic Waves Upon Klebsiella Pneumoniae, Saccharomyces Cerevisiae, Miyagawanella Felis, and Influenza Virus A

Hamre¹

1949

J Bacteriol

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Although the fact that high-frequency sound waves (9,000 to 800,000 cycles per second) disrupt living cells is now well established (Bergmann, 1938), few quantitative data are available, and the data now existing are difficult to compare because of variations in the way the experiments were conducted. Two types of high-frequency sound generators have been used: the magnetostriction oscillator, which produces vibrations at about 9,000 cycles per second, and the quartz crystal generator, in which the frequency of the sound depends upon the crystal and can be as high as 800,000 cycles per second. There are insufficient data at the present time to permit the selection of one sonic frequency as superior to all others. As a matter of fact, Stumpf, Green, and Smith (1946) have stated that the degree of disintegration of bacteria by ultrasonic waves is related to the amplitude of intensity of the wave rather than to the frequency, but they do not give any experimental data to support this statement. The present report deals with experiments using a quartz crystal generator of ultrasonic waves.In ultrasonic experiments using a quartz crystal generator the following factors must be taken into consideration: (1) the size of the crystal, (2) the frequency of the crystal, (3) the amplitude or intensity of the wave, (4) the distance between the top of the crystal and the bottom of the container used for the material to be treated, (5) the type of container used for the material to be treated, (6) the depth of liquid being treated, (7) the composition of the suspending medium for the cells being treated, and (8) the type of cooling system used.

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Section: Resultsmentioning

confidence: 99%

The Effect of Ultrasonic Waves Upon Klebsiella Pneumoniae, Saccharomyces Cerevisiae, Miyagawanella Felis, and Influenza Virus A

Hamre¹

1949

J Bacteriol

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“…The authors are unable to explain away the killing effects of R-F energy per se reported by other workers, notably Beckwith et al (1931), Fabian et al (1933), Yen et al (1934) Fleming (1944)) and Nyrop (1946). Aside from the differences in frequencies employed, there is the possibility that localized overheating or some experimental artifact might be responsible for the observed lethalities.…”

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confidence: 62%

“…Beckwith et al (1931) reported significant reductions in the numbers of Saccharomyces ellipsoideus and other yeast irradiated with R-F waves. In three cases, sterilization of the yeast suspension was achieved in 15 min.…”

Section: Introductionmentioning

confidence: 96%

“…This work was done to determine if 60 mc/sec R-F energy has a selective killing effect on microorganisms other than that attributable to heat. Beckwith et al (1931) reported significant reductions in the numbers of Saccharomyces ellipsoideus and other yeast irradiated with R-F waves. In three cases, sterilization of the yeast suspension was achieved in 15 min.…”

Section: Introductionmentioning

confidence: 98%

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Lethality of Radio‐Frequency Energy upon Microorganisms in Liquid, Buffered, and Alcoholic Food Systems

Carroll

Lopez

1969

Journal of Food Science

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This work was done to determine if 60 mc/sec R-F energy has a selective killing effect on microorganisms other than that attributable to heat. The organisms studied were Saccharomyces cerevisiae, Escherichia coli, and Bacillus subtilis. An aqueous buffer medium was used to suspend the microorganisms for the irradiation treatments.No killing effect of the R-F energy per se on the organisms was observed at any of the various buffer pH values, nor was there an observable synergistic killing effect of R-F energy and heat on the microorganisms in any of the buffers. However, a synergistic killing effect of ethanol and heat at 48.8"C was demonstrated on S. cerevisiae. Irradiating S. cerevisiae and E. coli in several liquid foods also failed to show a selective killing effect of R-F energy.

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“…In this latter case, in which destruction of microorganisms is reported to occur only by the action of microwaves, some attempts have been made to control and record the maximal temperature reached during exposure. Beckwith and Olson (1) reported that Saccharomyces ellipsoideus, as well as other yeasts, were significantly 1…”

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confidence: 99%

Procedure for Evaluating the Effects of 2,450- Megahertz Microwaves upon Streptococcus faecalis and Saccharomyces cerevisiae1

Lechowich

Beuchat

Fox

et al. 1969

Applied Microbiology

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Modifications of a commercial 2,450-megahertz microwave oven were made so that 6 ml of microbial suspension could be exposed to the microwave field for various periods of time. The microorganisms were contained in the central tube of a modified Liebig condenser positioned in the approximate geometric center of the oven cavity. Kerosene at-25 C was circulated through the jacket of the condenser during microwave exposure permitting microwaves to reach the microbial suspension. Flow rates of the kerosene were varied to permit the temperature of the suspension to range from 25 to 55 C during microwave exposure. Conductive heating experiments using similar temperatures were also conducted. A thermocouple-relay system was employed to measure the suspension temperature immediately after the magnetron shutoff. Continuous application of microwaves to suspensions of 108 to 109 Streptococcus faecalis or Saccharomyces cerevisiae per ml appeared to produce no lethal effects other than those produced by heat. Respiration rates of microwave-exposed S. cerevisiae were directly related to decreases in viable count produced by increased microwave exposure times.

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Ultrasonic Radiation and Yeast Cells

Cited by 17 publications

References 0 publications

The Effect of Ultrasonic Waves Upon Klebsiella Pneumoniae, Saccharomyces Cerevisiae, Miyagawanella Felis, and Influenza Virus A

The Effect of Ultrasonic Waves Upon Klebsiella Pneumoniae, Saccharomyces Cerevisiae, Miyagawanella Felis, and Influenza Virus A

Lethality of Radio‐Frequency Energy upon Microorganisms in Liquid, Buffered, and Alcoholic Food Systems

Procedure for Evaluating the Effects of 2,450- Megahertz Microwaves upon Streptococcus faecalis and Saccharomyces cerevisiae1

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