FT-IR SPECTROSCOPIC STUDIES ON MOLECULAR-INTERACTIONS OF CRYOPROTECTANT AGENTS WITH BACTERIA

Citation
W. Zeroual et al., FT-IR SPECTROSCOPIC STUDIES ON MOLECULAR-INTERACTIONS OF CRYOPROTECTANT AGENTS WITH BACTERIA, Biospectroscopy, 1(6), 1995, pp. 365-373
Citations number
43
Categorie Soggetti
Biophysics,Spectroscopy
Journal title
ISSN journal
10754261
Volume
1
Issue
6
Year of publication
1995
Pages
365 - 373
Database
ISI
SICI code
1075-4261(1995)1:6<365:FSSOMO>2.0.ZU;2-J
Abstract
Fourier transform infrared spectroscopy was used to investigate, witho ut any destructive interference, interactions of the cryoprotective ag ents, glycerol and dimethyl sulfoxide with Bradyrhizobium japonicum. T he intracellular spectrum of glycerol, obtained by subtracting the spe ctrum of control bacteria from that of glycerol-treated bacteria, show ed no differences in infrared features compared to that of pure glycer ol. This was not the case when dimethyl sulfoxide treatment was used. The intracellular spectrum displayed important modifications compared to that of the pure chemical. Spectral analysis showed that glycerol a nd dimethyl sulfoxide uptake required only a few minutes. Moreover, th e infrared features resulting from the presence of pure glycerol, in b acteria, were still existent for up to 2 or 3 hours after thawing proc ess. The deconvoluted Amide I and Amide II bands of bacterial proteins reflected important changes in secondary structure after treatment of bacteria with dimethyl sulfoxide ( increase in P-sheet and loss of ra ndom coil content). In contrast to glycerol, the cryoprotective action of dimethyl sulfoxide probably involves interactions with a wide rang e of intrabacterial species. (C) 1996 John Wiley & Sons, Inc.