Showing papers on "Sawdust published in 1975"

Wood and wood-based residues in animal feeds

Abstract: Cellulose is the most abundant, naturally renewable material on earth, It, and hemicellulose, make up about 70% of the dry weight of shrubs and trees. The cellulose of woody plants, however, is largely unavailable to ruminants because of the highly crystalline nature of the cellulose molecule and the existence of a lignin-carbohydrate complex. I f convenient ways can be found to enhance the availability of wood cellulose to enzymatic or microbiological systems, wood residues could provide an additional renewable energy feed supply for a world that can maintain no contingency reserve of feedstuffs. It would permit utilization of the large quantities of cellulosic residues that occur during harvest and manufacture of wood and cellulose products and provide a method of disposal of the used products. This article presents a summary of research conducted on the use of wood and wood-based materials in animal feeds a t the Forest Products Laboratory and the University of Wisconsin, and research in cooperation with the Tennessee Valley Authority, the U.S.D.A. Agricultural Research Service, Animal Nutrition Laboratory, Pennsylvania State University, and Auburn University.

Sugar production from agricultural woody wastes by saccharification with Trichoderma viride cellulase.

Abstract: The saccharification of agricultural woody wastes was studied using a commercial enzyme preparation, Cellulase onozuka, derived from Trichoderma viride or the solid culture extracts of the fungus. With the intention of producing sugar at low cost, a simple procedure of enzymatic saccharification of rice straw, bagasse, and sawdust was studied. Delignifying methods of these wastes were investigated using dilute sodium hydroxide solution and dilute peracetic acid. Rice straw and bagasse were effectively delignified by boiling in a 1% sodium hydroxide solution for 3 hr or by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a broad leaved tree (Machilus thunbergii) was delignified by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr and by subsequent boiling in diluted 1/5 peracetic acid for 1 hr. This type of sawdust was also delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a coniferous tree (Cryptomeria japonica) was delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr; however, the successive treatment by autoclaving with alkali solution and subsequent boiling with diluted peracetic acid failed to bring about the desired effect. The saccharification of delignified rice straw, bagasse, and sawdust was examined using Cellulase onozuka, wheat bran or rice straw solid culture at various substrate concentrations, resulting in the formation of 5 to 10% sugar solutions after incubation at pH 5.0, 45 degrees C for 48 hr. The optimum substrate concentration existed at around 10%. Reuse of cellulase solution and resaccharification of residual sawdust were considered to be inadequate.