Тип публикации: статья из журнала
Год издания: 2013
Идентификатор DOI: 10.1016/j.saa.2012.06.003
Ключевые слова: Bioluminescence, Americium-241, Humic substances, FTIR (DRIFT) spectroscopy, Poly-3-hydroxybutyrate, Photobacterium phosphoreum, FTIR, Americium, Bacteria, Cell culture, Ecology, Phosphorescence, Potassium, Radiation, Radioactivity, Reflection, Spectroscopic analysis, Fourier transform infrared spectroscopy, biomass, conference paper, cytology, drug effect, humic substance, infrared spectroscopy, luminescence, metabolism, methodology, microbial viability, Photobacterium, time, Luminescent Measurements, Spectroscopy, Fourier Transform Infrared, Time Factors
Аннотация: The integral bioluminescence (BL) intensity of live Photobacterium phosphoreum cells (strain 1883 IBSO), sampled at the stationary growth stage (20 h), was monitored for further 300 h in the absence (control) and presence of Am-241 (an alpha-emitting radionuclide of a high specific activity) in the growth medium. The activity conceПоказать полностьюntration of Am-241 was 2 kBq l(-1)%Am-241]= 6.5 x 10(-11) M. Parallel experiments were also performed with water-soluble humic substances (HS, 2.5 mg l(-1); containing over 70% potassium humate) added to the culture medium as a possible detoxifying agent. The BL spectra of all the bacterial samples were very similar (lambda(max) = 481 +/- 3 nm; FWHM =83 +/- 3 nm) showing that Am-241 (also with HS) influenced the bacterial BL system at stages prior to the formation of electronically excited states. The HS added per se virtually did not influence the integral BL intensity. In the presence of Am-241, BL was initially activated but inhibited after 180 h, while the system Am-241 + HS showed an effective activation of BL up to 300 h which slowly decreased with time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, applied to dry cell biomass sampled at the stationary growth phase, was used to control possible metabolic responses of the bacteria to the alpha-radioactivity stress (observed earlier for other bacteria under other stresses). The DRIFT spectra were all very similar showing a low content of intracellular poly-3-hydroxybutyrate (at the level of a few percent of dry biomass) and no or negligible spectroscopic changes in the presence of Am-241 and/or HS. This assumes the alpha-radioactivity effect to be transmitted by live cells mainly to the bacterial BL enzyme system, with negligible structural or compositional changes in cellular macrocomponents at the stationary growth phase. (c) 2012 Elsevier B.V. All rights reserved.
Журнал: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
Выпуск журнала: Vol. 100
Номера страниц: 171-175
ISSN журнала: 13861425
Место издания: OXFORD
Издатель: PERGAMON-ELSEVIER SCIENCE LTD