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The pretreatment of plant biomass negatively impacts the economics of many bioenergy and bioproduct processes due to the thermochemical requirements for deconstruction of lignocelluluose. An effective strategy to reduce these severity requirements is to pretreat the biomass with white-rot fungi, such as Trametes versicolor, which have the innate ability to deconstruct lignocellulose with a suite of specialized enzymes. In the present study, the effects of 12 weeks of pretreatment with a wild-type strain (52J) and a cellobiose dehydrogenase-deficient strain (m4D) of T. versicolor on hardwood and Miscanthus were explored. Both strains of T. versicolor led to significant decreases of insoluble lignin and significant increases of soluble lignin after acid hydrolysis, which suggests improved lignin extractability. The glucose yields after saccharification using an enzyme cocktail containing chitinase were similar or significantly higher with 52J-treated biomass compared to untreated hardwood and Miscanthus, respectively. The fungal treated biomass, regardless of the strain used, also showed significant increases in energy content and compressive strength of pellets. Overall, the use of T. versicolor as a pretreatment agent for hardwood and Miscanthus could be an environmentally friendly strategy for conversion technologies that require delignification and saccharification, and/or processes that require densification and transport.

Natural and anthropogenic soil degradation is resulting in a substantial rise in the extension of saline and industrially-polluted soils. Phytoremediation offers an environmentally and economically advantageous solution to soil contamination. Three growth trials were conducted to assess the stress tolerance of native Canadian genotypes of Populus balsamifera L., Salix eriocephala Michx., and one hybrid willow (S. discolor × S. dasyclados) to salinity and hydraulic fracturing (fracking) wastewater. Thirty-three genotypes were grown in NaCl or fracking wastewater solutions between 0 and 7 mS−1 over a period of 3–4 months. P. balsamifera was observed to be relatively salt-intolerant compared to S. eriocephala and hybrid willow, which is likely caused by an inability of P. balsamifera to restrict Na+ translocation. Photosynthesis and transpiration decreased with salinity treatments, and severe reductions occurred with exposure to fracking solutions. Raffinose and stachyose content was tripled in leaf and root tissues. In willows, Na+ was primarily confined to root tissues, Cl− accumulated up to 5% dry weight in leaves, and K+ was translocated from roots to leaves. Willow genotypes CAM-2 and STL-2 displayed the greatest maintenance of growth and resistance to necrotic symptoms in all trials, suggesting that these genotypes may be useful for practical application and further field study.

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