@article{sulis_jiang_yang_marques_matthews_miller_lan_cofre-vega_liu_sun_et al._2023, title={Multiplex CRISPR editing of wood for sustainable fiber production}, volume={381}, ISSN={["1095-9203"]}, url={http://europepmc.org/abstract/med/37440632}, DOI={10.1126/science.add4514}, abstractNote={The domestication of forest trees for a more sustainable fiber bioeconomy has long been hindered by the complexity and plasticity of lignin, a biopolymer in wood that is recalcitrant to chemical and enzymatic degradation. Here, we show that multiplex CRISPR editing enables precise woody feedstock design for combinatorial improvement of lignin composition and wood properties. By assessing every possible combination of 69,123 multigenic editing strategies for 21 lignin biosynthesis genes, we deduced seven different genome editing strategies targeting the concurrent alteration of up to six genes and produced 174 edited poplar variants. CRISPR editing increased the wood carbohydrate-to-lignin ratio up to 228% that of wild type, leading to more-efficient fiber pulping. The edited wood alleviates a major fiber-production bottleneck regardless of changes in tree growth rate and could bring unprecedented operational efficiencies, bioeconomic opportunities, and environmental benefits.}, number={6654}, journal={SCIENCE}, author={Sulis, Daniel B. and Jiang, Xiao and Yang, Chenmin and Marques, Barbara M. and Matthews, Megan L. and Miller, Zachary and Lan, Kai and Cofre-Vega, Carlos and Liu, Baoguang and Sun, Runkun and et al.}, year={2023}, month={Jul}, pages={216-+} }
 @article{jiang_sun_kollman_chang_jameel_2023, title={Structure and property variations of mixed hardwood kraft lignins}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2023.2262974}, abstractNote={Abstract Kraft lignin as an emerging renewable feedstock can be used to produce fuels, chemicals, and materials. Hardwood kraft lignin bears intrinsic variation due to wood species and the isolation process. The structure and property variation of hardwood kraft lignin could introduce new challenges and opportunities for its application. To better understand such variation, seven kraft lignin samples, originated from southern mixed hardwood (North America), northern mixed hardwood (North America), and Asian mixed hardwood, were isolated from commercial kraft pulping black liquor using both LignoBoost and LignoForce processes. Modern analytical techniques were used to elucidate the characteristics of mixed hardwood kraft lignins, including chemical composition, molecular weight, functional groups, and thermal properties. All lignin samples had a lignin content over 90% (92% to 96%) with one exception, which was northern mixed hardwood kraft lignin with 86% of lignin content and 6% polysaccharides. The elemental and methoxy analyses revealed the expected variation of hardwood kraft lignins with the methoxy content ranging from 0.85 to 1.20 per C9 unit. The weight average molecular weight exhibited a higher variation (from 4800 to 1895 Da) with a descending order of southern mixed hardwood kraft lignins, northern mixed hardwood lignins, and Asian mixed hardwood lignins. The aliphatic hydroxy groups ranged from 14 to 25 per 100 C9 units, and phenolic hydroxy groups ranged from 65 to 112 per 100 C9 units. The catecholic group content ranged from 12 to 34 per 100 C9 units, which is higher than softwood kraft lignin. The lignins isolated from the rapid displacement heating (RDH) pulping process were more condensed than from the regular kraft pulping process. 2D HSQC and quantitative 13C NMR revealed the drastic structure change upon kraft pulp with the low abundance of native lignin linkages and formation of new interunit linkages, such as stilbene, enol ethers, and 1-1’/5’. The S/G ratio was calculated using 2D HSQC spectra correcting for signal shift caused by the catecholic groups.}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Jiang, Xiao and Sun, Runkun and Kollman, Matthew and Chang, Hou-min and Jameel, Hasan}, year={2023}, month={Sep} }
 @article{kollman_jiang_sun_zhang_li_chang_jameel_2023, title={Towards jet fuel from technical lignins: Feedstock-catalyst-product interactions revealed during catalytic hydrogenolysis}, volume={451}, ISSN={["1873-3212"]}, DOI={10.1016/j.cej.2022.138464}, abstractNote={One-pot conversion of technical lignins to jet fuel is limited by recondensation of unstable intermediates. A two-stage process that first generates stabilized fragments by reductive depolymerization, then upgrades oligomers to hydrocarbons may increase yield. Insights into factors affecting initial depolymerization of industrially relevant lignins were revealed, whereas many studies have focused on upgrading bio-oil or model compounds. Feedstocks, catalysts, and process conditions were varied to identify effects on product composition. Hydrogen and temperature synergistically suppressed coking during pine kraft depolymerization to increase monomer production. Ruthenium was more effective than cobalt at limiting solid residue and improving liquid product yield by promoting hydrogenation and hydrogenolysis. Besides ruthenium, a strong acid-base catalyst effectively deconstructed hardwood biorefinery lignin, targeting alkyl-aryl ether bonds. Ruthenium and zinc converted hardwood kraft lignin to oligomers most suitable for upgrading to jet fuel-range hydrocarbons based on yield (79 % on dry lignin), weight-average molecular weight (1290 g/mol), and chemical structure.}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Kollman, Matthew S. and Jiang, Xiao and Sun, Runkun and Zhang, Xia and Li, Wenzhi and Chang, Hou-min and Jameel, Hasan}, year={2023}, month={Jan} }
 @article{vera_vivas_urdaneta_franco_sun_forfora_frazier_gongora_saloni_fenn_et al._2023, title={Transforming non-wood feedstocks into dissolving pulp via organosolv pulping: An alternative strategy to boost the share of natural fibers in the textile industry.}, volume={429}, ISSN={["1879-1786"]}, url={https://doi.org/10.1016/j.jclepro.2023.139394}, DOI={10.1016/j.jclepro.2023.139394}, abstractNote={This work evaluates wheat straw, switchgrass, and hemp hurd as potential alternatives for producing dissolving pulp using sulfur dioxide (SO2)-ethanol-water (SEW) pulping. The SEW process is described in detail for wheat straw, and the best pulping conditions for this feedstock were 130 °C, 4 h, and 10% SO2 concentration, comprised in a sulfur-ethanol-water ratio of 10-45-45. This resulted in a viscose-grade pulp with 93% α-cellulose, 2.0% hemicelluloses, <0.1% lignin, 0.2% ash content, and a viscosity of 4.7 cP. The best pulping conditions for wheat straw were applied to switchgrass and hemp hurd. Wheat straw and switchgrass had similar pulp quality, while hemp hurd pulp had a higher hemicellulose content and lower viscosity. This work suggests that non-wood feedstocks such as wheat straw and switchgrass can be promising alternatives for dissolving pulp production, which can help reduce the pressure on the textile industry to increase the use of natural fibers and mitigate the environmental impact of non-biodegradable synthetic fibers.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Vera, Ramon E. and Vivas, Keren A. and Urdaneta, Fernando and Franco, Jorge and Sun, Runkun and Forfora, Naycari and Frazier, Ryen and Gongora, Stephanie and Saloni, Daniel and Fenn, Larissa and et al.}, year={2023}, month={Dec} }
 @article{jiang_assis_kollman_sun_jameel_chang_gonzalez_2020, title={Lignin fractionation from laboratory to commercialization: chemistry, scalability and techno-economic analysis}, volume={22}, ISSN={["1463-9270"]}, url={https://doi.org/10.1039/D0GC02960B}, DOI={10.1039/d0gc02960b}, abstractNote={A detailed techno-economic analysis on industrial scale lignin fractionation using green solvents.}, number={21}, journal={GREEN CHEMISTRY}, publisher={Royal Society of Chemistry (RSC)}, author={Jiang, Xiao and Assis, Camilla and Kollman, Matthew and Sun, Runkun and Jameel, Hasan and Chang, Hou-min and Gonzalez, Ronalds}, year={2020}, month={Nov}, pages={7448–7459} }
 @article{huang_sun_chang_yong_jameel_phillips_2019, title={Production of Dissolving Grade Pulp from Tobacco Stalk Through SO2-ethanol-water Fractionation, Alkaline Extraction, and Bleaching Processes}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.3.5544-5558}, abstractNote={The objective of this study was to evaluate the possibility of producing dissolving grade pulp from tobacco stalk through combining SO2-ethanol-water (SEW) fractionation, alkaline extraction, and bleaching with oxygen (O), chlorine dioxide (D), alkaline extraction with hydrogen peroxide (Ep), and hydrogen peroxide (P) (OD0(Ep)D1P). The results showed that the optimum SEW cooking condition to remove the original xylan and lignin in tobacco stalk to an acceptable level was 6% SO2 charge (by weight) at 135 °C for 180 min. A bleachable pulp (Kappa number of 21.5) was produced from the SEW-treated tobacco stalk via a subsequent 1% NaOH extraction. After the OD0(Ep)D1P sequence bleaching, the bleached pulp showed a high brightness (88.1% ISO) and a high α-cellulose content (94.9%). The viscosity (15.8 cP) and the residual xylan content (4.4%) of the pulp were within acceptable levels for dissolving pulp production. Thus, tobacco stalk was shown to be a viable raw material for dissolving pulp production following a SEW treatment, alkaline extraction, and a conventional bleaching sequence.}, number={3}, journal={BIORESOURCES}, author={Huang, Caoxing and Sun, Runkun and Chang, Hou-min and Yong, Qiang and Jameel, Hasan and Phillips, Richard}, year={2019}, month={Aug}, pages={5544–5558} }