EMF-Portal | Different effects of microwave energy and conventional heat on the activity of a thermophilic beta-galactosidase from Bacillus acidocaldarius

Different effects of microwave energy and conventional heat on the activity of a thermophilic beta-galactosidase from Bacillus acidocaldarius med./bio.

By: La Cara F, Scarfi MR, D'Auria S, Massa R, d'Ambrosio G, Franceschetti G, Rossi M, De Rosa M

Published in: Bioelectromagnetics 1999; 20 (3): 172-176

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Aim of study (acc. to author)

To test the effect of microwave irradiation on the activity of the thermostable enzyme β-galactosidase purified from the thermoacidophilic eubacterium Bacillus acidocaldarius.

Endpoint

Exposure

Exposure	Parameters
Exposure 1: 10.4 GHz Exposure duration: 15, 30, 45, 60 min	SAR: 1.7 W/g average over time
Exposure 2: 10.4 GHz Exposure duration: continuous for 1 h	SAR: 1.1 W/g average over time SAR: 1.7 W/g average over time

General information

control samples were kept at 70 °C without microwave irradiation

Exposure 1

Main characteristics

Frequency	10.4 GHz
Type	electromagnetic field
Exposure duration	15, 30, 45, 60 min

Exposure setup

Exposure source	rectangular waveguide 22.86 mm x 10.16 mm
Setup	samples placed inside the waveguide

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	1.7 W/g	average over time	calculated	-	-

Exposure 2

Main characteristics

Frequency	10.4 GHz
Type	electromagnetic field
Exposure duration	continuous for 1 h

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	1.1 W/g	average over time	calculated	-	-
SAR	1.7 W/g	average over time	calculated	-	-

Reference articles

d'Ambrosio G et al. (1995): Genotoxic Effects of Amplitude-Modulated Microwaves on Human Lymphocytes Exposed in Vitro under Controlled Conditions

Exposed system:

bacterium
Bacillus acidocaldarius

Methods Endpoint/measurement parameters/methodology

cell function: enzyme activity (β-galactosidase) (photometrically determination of enzyme product)

Investigated system:

isolated bio./chem. substance

Time of investigation:

after exposure

Main outcome of study (acc. to author)

An irreversible enzym inactivation induced by microwave irradiation was observed, depending on protein concentration and microwave intensity. This effect was not found at high protein concentration. Enzym inactivation was not observed in control experiments without microwave irradiation.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

Vojisavljevic V et al. (2011): Low intensity microwave radiation as modulator of the L-lactate dehydrogenase activity

Fortune JA et al. (2010): Radio frequency radiation causes no nonthermal damage in enzymes and living cells

Vojisavljevic V et al. (2010): Review of studies on modulating enzyme activity by low intensity electromagnetic radiation

Homenko A et al. (2009): Effects of 100 GHz radiation on alkaline phosphatase activity and antigen-antibody interaction

Pirogova E et al. (2008): Non-thermal effects of 500MHz - 900MHz microwave radiation on enzyme kinetics

Different effects of microwave energy and conventional heat on the activity of a thermophilic beta-galactosidase from Bacillus acidocaldarius med./bio.

Aim of study (acc. to author)

Endpoint

Exposure

General information

Exposure 1

Main characteristics

Exposure setup

Parameters

Exposure 2

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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