Organisms Commons^™

Phanerochaete Chrysosporium Pretreatment Of Biomass To Enhance Solvent Production In Subsequent Bacterial Solid-Substrate Cultivation, Wanying Yao, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

This study investigated pretreatment of corn stover using solid substrate cultivation (SSC) of Phanerochaete chrysosporium (P. chrysosporium) to improve subsequent accessibility to cellulose. Thereafter, Clostridium thermocellum (C. thermocellum) was directly inoculated onto the pretreated biomass to accomplish hydrolysis, followed by solventogenesis by introducing Clostridium beijerinckii (C. beijerinckii).

An enzyme suite containing laccase, lignin peroxidase and manganese peroxidase activity was detected during the cultivation of P. chrysosporium on corn stover within 288 h at an initial moisture content 𝓌_H2O = 80% (mass of water/total mass). Incubation factors, such as substrate moisture content and cultivation …

Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

We report development of a genetic system for making targeted gene knockouts in Clostridium thermocellum, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the pyrF gene. The ΔpyrF strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of pyrF from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed pyrF, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely pta, which encodes …