Structural analysis of lime wood biodegraded by white rot fungi through infrared and two dimensional correlation spectroscopy techniques

• Investigation of the lime wood biodegradation by white rot fungi.
• Evaluation of the structure by infrared spectroscopy and 2DCOS.
• Degradation starts by the modification of the OH groups from primary alcohols.
• Formation of new CO, CO structures after white rot decay.

The action of the white rot fungi Phanerochaete crisosporium on the structure of lime wood (Tilia cordata) has been studied. The degree of decay was determined by weight loss, which was of 37% after 110 days. The samples were further analyzed by infrared and two dimensional correlation spectroscopy.The recorded spectra for different intervals of decay indicate variations in the intensities and width or wavenumber shifts of the bands assigned, both, for lignin and carbohydrates. An increase in the intensities of the bands from the carbonyl region due to formation of new structures, accompanied by the reduction of the methoxyl and methyl/methylene groups in lignin was evidenced. Further, the differences between reference and decayed wood spectra were examined in detail using 2DCOS spectroscopy and the second derivative analysis and the sequential order of modifications were established.