Cet article a été publié dans un numéro de la revue, cliquez ici pour y accéder
Awareness of the potential role of bacterial decay of wood in water-saturated environments is relatively recent, but has led to great concern that foundation poles under historical buildings in Europe as well as waterlogged archaeological remains are under serious bacterial threat. The evaluation of the degree of degradation is essential in developing stabilisation and/or conservation strategies. Most evaluations of wood degraded by bacteria are based on physical characterization (De Jong, 1977; McConnachie et al., 2008) [1, 2] or microscopic observations (Grinda, 1997; Klaassen, 2005; Paajanen et al. 1988) [3, 4, 5]. The chemical composition, especially lignin content, is also a good indicator for degree of degradation (Gelbrich et al., 2008; Gelbrich, 2009) [6, 7]. These methods are known as destructive analyses and are very time and material consuming. The present study correlated changes in chemistry with the degree of microscopically detectable degradation in order to find new ways in evaluating the degree of bacterial wood degradation. The characterization of waterlogged softwood samples by means of infrared spectroscopy reflects results of chemical analyses but a direct quantitative analysis of wood compounds by Fourier Transform Infrared (FTIR) spectroscopy is problematic. Due to the linear regression between lignin content which was determined chemically and the absorbance values of lignin in FTIR spectra a calibration curve could be drawn up. Reversed on this database it was shown that FTIR measurements are practical in evaluating the degree of bacterial degradation in softwood with the advantage of smallest amounts of sample material required, the enhanced rapidity and simplicity of this method.
Keywords : Wood degradation, Bacteria, Decay evaluation, Softwood, FTIR, Klason lignin