| The effect that biotreatment with Ceriporiopsis subvermispora has on sugar maple (Acer saccharum) chips, and its ability to enhance the extraction of hemicellulose was investigated.; The effect of the biotreatment on the chip was analyzed to assess selectivity towards the removal of the non-carbohydrate mass as well as the physical and chemical changes in the chips, which can affect the removal of hemicelluloses. The loss of lignin from the chips increased with the loss of mass during biotreatment and represented the majority of the mass loss. Klason lignin losses were 12%, 29.8%, and 41.1% in biotreated chips with total mass losses of 3.8%, 10.6%, and 18.6%. Images taken with a scanning electron microscope show degradation and erosion of the cell walls, which result in a more open structure. The opening of the structure was confirmed by analysis of the mass of water in a given volume of saturated biotreated chips. The pH of water extract of the chips was also seen to decrease after the biotreatment process dropping from 5.29 for untreated wood to 3.26, and 3.23 for biotreated chips with mass losses of 10.6% and 18.6% respectively.; The benefits of biotreatment on the alkali extraction or hydrolysis of hemicellulose was then evaluated. The hemicelluloses that can be extracted with 25% KOH from the maple wood chips increased with even moderate biotreatment. Xylan is the primary hemicellulose found in hardwood and was measured as 19.4% of the mass of the untreated wood. The mass of xylan that was extracted increased from 2.9% for untreated chips to 6.7%, 7.1%, and 7.6% of the raw wood mass, for biotreated wood with mass losses of 3.8%, 10.6% and 18.6%, respectively.; Autohydrolysis of the maple chips with temperatures in the range of 140°C to 180°C was used to extract hemicellulose from the maple chips. The total sugars and the xylose in the extract correlated well to the total non-volatile solids content of the extract for both biotreated and untreated chips at all temperatures and times used for the experiments. From these correlations a predicted maximum xylose content equivalent to 10.6% of the mass of the raw wood can be removed and retained in the extract. The rate of removal from the biotreated chips was found to be twice as fast as from the untreated chips at each of the temperatures used.; Key words. Ceriporiopsis subvermispora, white-rot fungi, bio-delignification, sugar maple, hemicellulose, xylan, carbohydrate, alkali extraction, autohydrolysis... |
