Study type: Medical/biological study (experimental study)

Response of Aspergillus nidulans and Physarum polycephalum to microwave irradiation. med./bio.

Published in: J Microw Power 1980; 15 (2): 75-80

Aim of study (acc. to author)

To investigate the effects of microwave exposure on two different kinds of fungi.

Background/further details

The organisms studied were: 1) Aspergillus nidulans, an Ascomycete and 2) Physarum polycephalum, a Myxomycete. Spores of A. nidulans were exposed before and during germination to investigate changes in survival rate and morphological appearance. On P. polycephalum the incorporation of radioactive labeled 3H-Thymine into DNA under microwave exposure was studied.
(evaluator's notice: the authors have used Physar-i-um in the headline and Physarum in the text. According to the NCBI taxonomy database the latter orthography is the right one.)

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: 1 h
Exposure 2: 2.45 GHz
Modulation type: pulsed
Exposure duration: 1 h

Exposure 1

Main characteristics
Frequency 2.45 GHz
Charakteristic
Exposure duration 1 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Additional info Control cultures were treated simultaneously; one set of controls were incubated under standard conditions (9 or 25), and thermal controls were incubated in a water bath at the same temperature (22°C) of those subjected to irradation.
Parameters
Measurand Value Type Method Mass Remarks
power density 100 mW/cm² mean measured - -

Exposure 2

Main characteristics
Frequency 2.45 GHz
Charakteristic
Exposure duration 1 h
Modulation
Modulation type pulsed
Pulse width 1 µs
Packets per second 600
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 100 mW/cm² mean measured - -

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No changes in survival rate and morphological mutations were found in A. nidulans.
The investigation on the 3H-Thymine incorporation into DNA by P. polycephalum showed the following result: The incorporation rate found under conditions of microwave exposure was nearly five times greater than in control group and about twice than found in thermal control group. But on the basis of the results a simple thermal activation could not be excluded; in other words: the observed increase can not clearly ascribe to exposure specifc parameters alone.

Study character:

Study funded by

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