Develop Biological Systems for Lignocellulose Conversion

摘要

Research was undertaken to develop biological processes for converting lignocelluloses. The study had two objectives: (1) to explore the potential for using a lignin-degrading system to partially delignify substrates, thereby improving polysaccharidase digestibility; and (2) to develop, from anaerobic, thermophilic bacteria, an improved cellulolytic enzyme system for cellulose saccharification. Three conclusions were drawn using the white-rot fungus, Phanerochaete chrysosporium, to delignify lignocelluloses in industrial processes. First, lignin decomposition is inherently a slow process in comparison to cellulose or glucose catabolism. Second, important culture parameters influencing decomposition of lignin in lignocellulosics include nutrient nitrogen concentration, aeration efficiency, and type of lignin. Third, degradation of the polysaccharide portion of lignocellulosics can be suppressed by adding glucose to the fermentation process. Steps involved in the enzymatic degradation of cellulose are discussed, one of the most important of which is the formation of long, linear chains of anhydroglucose units. Procedures for the continuous assay of dyed cellulose preparations are described. Examination is provided of the degradation of different dyed cellulose preparations by cellulase.