Enzymatic hydrolysis of waste cellulose

作者：Mary Mandels, Lloyd Hontz, John M. Nystrom · 发表于：Biotechnology and Bioengineering · 年份：1974 · DOI：10.1002/bit.260161105 · 被引用次数：460 · 研究领域：Biofuel production and bioconversion、Enzyme Production and Characterization、Advanced Cellulose Research Studies

Abstract Waste cellulose was a suitable carbon source for cellulose production by Trichoderma viride. The enzyme can be produced in submerged fermentation using newspaper as a growth substrate. A variety of pure and complex cellulosic materials were hydrolyzed by culture filtrates. Saccharification of 5% slurries after 48 hr ranged from 2–92%. The rate and extent of hydrolysis was controlled by degree of crystallinity, particle size, and presence of impurities. Newspaper was used to evaluate methods for the pretreatment of substrate. The best pretreatment was ball milling which gave good size reduction, maximum bulk density, and maximum susceptibility. Hammer milling, fluid energy milling, colloid milling, or alkali treatments were less satisfactory. Dissolving cellulose in cuprammonium, or carbon disulfide (Viscose) and then reprecipitating gave a susceptible, but low bulk density product. However the susceptibility was lost if the substrate was dried. Because of costs, low bulk density, necessity of keep ing the substrate wet, and generation of chemical waste streams dissolving cellulose to increase reactivity does not seem a practical approach. Cellulose fractions separated from municipal trash or agricultural residues such as milled fibres from bovine manure are promising substrates for conversion.