Two different mechanisms of low-intensity laser photobiological effects on Escherichia coli

Tiina Karu, Olga Tiphlova, Rinat Esenaliev, Vladilen Letokhov

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Bacterial suspensions in a phosphate buffer were irradiated at wavelengths λ of 632.8, 1066 and 1286 nm, incubated in Hottinguer broth for 60 min and assayed for viability by the standard surface-plating technique. The difference between the number of viable cells in the irradiated culture and the control was termed growth stimulation. Irradiation of the bacteria with an HeNe laser (632.8 nm) or semiconductor lasers at 1066 and 1286 nm at various intensities and irradiation times produced two maxima in the growth stimulation vs. dose curve. The first maximum, in all cases, occurred near 50 J m-2, and the reciprocity law was obeyed. The second maximum occurred at an irradiation time of 100 s irrespective of the particular radiation intensity, and the reciprocity law was not obeyed. It is assumed that two different mechanisms are responsible for these two maxima in the growth stimulation vs. dose curve.

Original languageEnglish (US)
Pages (from-to)155-161
Number of pages7
JournalJournal of Photochemistry and Photobiology, B: Biology
Volume24
Issue number3
DOIs
StatePublished - 1994
Externally publishedYes

Fingerprint

Escherichia
Escherichia coli
lasers
Lasers
irradiation
stimulation
Irradiation
Growth
semiconductors
Semiconductor Lasers
Gas Lasers
broths
dosage
Plating
Semiconductor lasers
wavelengths
Suspensions
Bacteria
Buffers
Phosphates

Keywords

  • Escherichia coli WP2
  • HeNe laser
  • Low-poser laser effects
  • Reciprocity law
  • Semiconductor lasers

ASJC Scopus subject areas

  • Plant Science
  • Bioengineering
  • Physical and Theoretical Chemistry

Cite this

Two different mechanisms of low-intensity laser photobiological effects on Escherichia coli. / Karu, Tiina; Tiphlova, Olga; Esenaliev, Rinat; Letokhov, Vladilen.

In: Journal of Photochemistry and Photobiology, B: Biology, Vol. 24, No. 3, 1994, p. 155-161.

Research output: Contribution to journalArticle

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