Bioconversion of plant biomass to ethanol. Final report, 15 December 1976-31 December 1978

Abstract

Two approaches to ethanol production via thermophilic mixed culture fermentation of pretreated wood were investigated. The initial studies of wood biodelignification by Chrysosporium pruinosum and subsequent mixed culture fermentation to ethanol using a cellulolytic strain of sporocytophaga and a strain of Bacillus stearothermophilus proved to be premature for a development effort. Studies of the fermentation of S0 2 /steamtreated poplar by a mixed culture of C. thermocellum and C. thermosaccharolyticum were, however, technically and economically promising. Wood pretreatment to enhance microbial utilization, the microbiology and biochemistry of pure and mixed culture fermentation of cellulose by C. thermocellum and C. thermocellum and C. thermosaccharolyticum, and techniques for improving ethanol tolerance and yield were investigated. Considerable progress in overcoming the technical barriers to efficient ethanol production from wood have been demonstrated; however, additional studies and development work are required before technical feasibility can be established.