Determination of fungal activity in modified wood by means of micro-calorimetry and determination of total esterase activity

Beech and pine wood blocks were treated with 1,3-dimethylol-4,5-dihydroxyethylen urea (DMDHEU) to increasing weight percent gains (WPG). The resistance of the treated specimens against Trametes versicolor and Coniophora puteana, determined as mass loss, increased with increasing WPG of DMDHEU. Metabolic activity of the fungi in the wood blocks was assessed as total esterase activity (TEA) based on the hydrolysis of fluorescein diacetate and as heat or energy production determined by isothermal micro-calorimetry. Both methods revealed that the fungal activity was related with the WPG and the mass loss caused by the fungi. Still, fungal activity was detected even in wood blocks of the highest WPG and showed that the treatment was not toxic to the fungi. Energy production showed a higher consistency with the mass loss after decay than TEA; higher mass loss was more stringently reflected by higher heat production rate. Heat production did not proceed linearly, possibly due to the inhibition of fungal activity by an excess of carbon dioxide

Crystallization and preliminary X-ray analysis of the catalytic domain of endoglucanase from Clostridium cellulolyticum.

International audienceThe catalytic domain of an endoglucanase belonging to family A (CelCCA) from an anaerobic bacterium (Clostridium cellulolyticum) has been crystallized in a form suitable for X-ray diffraction analysis. The crystals have been grown in the presence of polyethylene glycol 4000 using the vapour diffusion technique. The crystals, which diffract to 2.0 A resolution, belong to the orthorhombic space group P2(1)2(1)2(1) and have the following cell constants: a = 52.4 A, b = 76.2 A and c = 113.5 A.The catalytic domain of an endoglucanase belonging to family A (CelCCA) from an anaerobic bacterium (Clostridium cellulolyticum) has been crystallized in a form suitable for X-ray diffraction analysis. The crystals have been grown in the presence of polyethylene glycol 4000 using the vapour diffusion technique. The crystals, which diffract to 2.0 A resolution, belong to the orthorhombic space group P2(1)2(1)2(1) and have the following cell constants: a = 52.4 A, b = 76.2 A and c = 113.5 A