查看更多>>摘要：? 2022 Elsevier B.V.Urtica dioica L. (stinging nettle) is a neglected underutilized species, with potential as a future multi-purpose crop. To address the requisite for information on the influence of agronomical factors on health promoting bioactive components in leaf material under organic management, commercial stinging nettle was cultivated in three locations (Emilia Romagna, Italy) and analyzed over four harvests (September 2020 - September 2021). Significantly higher levels of polyphenol and flavonoid components as well as antioxidant activity (ferric reducing antioxidant potential [FRAP] and 1,1-diphenyl-2-picrylhydrazyl [DPPH]) were obtainable in May and July in the second cultivation year. Only the location at Lizzano yielded significantly higher biomass in combination with higher polyphenol content and FRAP in May, DPPH in May and July and ascorbate in July and September. Throughout 2021, limiting water supply was the major determinant for the significantly lower yield and higher polyphenol (flavonoid) content, respectively, at the rainfed location of Tresigallo. Temperature and growing degree days were inversely correlated to polyphenol content and antioxidant activity, implicating temperature as the major determinant of the latter under non-limiting water supply in the mountainous region of Lizzano. Provided agronomic practices are implemented, including effective weed removal, uniform water supply (supplementary irrigation) and organic amendments, satisfactory yields are obtainable combined with high levels of bioactive components. This shows promise for stinging nettle cultivation towards increased use in the medicinal/herbalist sector.
de Souza Junior J.P.de Mello Prado R.Cazetta J.O.Campos C.N.S....
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查看更多>>摘要：? 2022 Elsevier B.V.Foliar spraying of a boron (B) + silicon (Si) mixture (1.50 g L-1 of B + 1.15 g L-1 of Si) during the reproductive stage of cotton plants could benefit both crop yield and fiber quality; however, further research is needed to confirm this hypothesis. Two experiments were carried out under field conditions, using the FM 906 GLT cotton cultivar, with experiment I conducted in the 2018/2019 growing season and II in 2019/2020. A randomized block design was used for both experiments, consisting of four treatments: water; foliar boron; foliar silicon; and foliar boron + silicon and six replications. A preliminary laboratory test was performed to assess the turbidity of B and Si solutions and determine their compatibility in a mixture. Four foliar applications were performed, beginning in reproductive stage B1, at intervals of 7–11 days. Foliar spraying of B alone was efficient in increasing concentrations of the micronutrient in cotton leaves and fiber. Silicon foliar application was also efficient in raising concentrations in leaves and fiber. Silicon + boron proved to be efficient in supplying cotton plans with both the micronutrient and the element. The internal CO2 concentration and photosynthetic rate of plants treated with B, Si or B+Si were higher than those observed in controls, with no difference between these treatments. The addition of Si to the boron spray solution (B+Si) and Si application alone (Si) increased WUE, with no difference between these treatments, compared with B and controls. Boron, Si and B+Si increased cotton fiber yield, in relation to the control treatment. Individual and combined (B+Si) application of B and Si increased the micronaire values and cotton fiber length in both growing seasons studied. Applying only B or Si also improved the tensile strength of cotton fibers in relation to controls and the highest value for this variable in both experiments was obtained when plants were treated with the B+Si mixture. Foliar spraying of B reduced the short fiber content when compared to controls and applying Si alone or added to the boron solution produced the lowest result for this parameter. Our results demonstrate that foliar Si spraying has an equivalent effect to B on the yield and fiber quality of cotton, and that combining the two elements is particularly beneficial to cotton fiber, improving its tensile strength and reducing short fiber content.
查看更多>>摘要：? 2022 Elsevier B.V.Highly stable catalysts were prepared by wet impregnation of blast furnace dust (BFD) in Na2CO3·H2O, Na2CO3·10H2O, NaHCO3 and Na2CrO4 solution and subsequent calcination at 300–600 °C. At low temperature of 65 °C for 2 h with methanol/oil molar ratio of 15/1, high biodiesel yield of 100 wt% was obtained with for both Na2CO3·H2O@BFD300 and Na2CO3·H2O@BFD400 catalyst (impregnating with Na2CO3·H2O solution and calcining at 300 and 400 °C) at 7 wt% for the first use. Na2CO3·H2O@BFD300 catalyst exhibited outstanding stability and recyclability with biodiesel yield of 100 wt% at the fifth use (93 wt% at the twelfth use) owing to the formation of stable and active nanocomponents of NaFeO2 (32.42 nm) and magnetic nanocomponent of Fe3O4 (size of 3.14 nm and magnetization of 6.16 Am2/kg). This study finds a solution to use solid waste for the green production of biodiesel.
查看更多>>摘要：? 2022 Elsevier B.V.The effect of variable O2 concentrations (5%, 10%, 15%, and 21%) in the injection mixing gas was examined on the properties of MgO/MgAl2O4 nanocatalysts created with solution combustion method for biofuel production. The results of XRD, FESEM, TEM, EDX, BET, FTIR and TG/DTG manifested that among all above-mentioned O2 contents injected into synthesis pot, the 21% O2 sample provides the possibility for the fuel to undergo complete combustion leading to superior characteristics of this nanocatalyst including better dispersion of MgO on the support, well-formed crystals, higher surface area with large pore volume and higher catalytic performance during transformation of vegetable fats to biofuel (98.2%) compared to the other samples without any gas injection or with lower oxygen contents. The conversion of air injected sample indicated only 2.8% connversion loss after five rounds of use, indicative of a mesoporous catalyst with still an acceptable conversion rate (93.8%) for biodiesel production.
查看更多>>摘要：? 2022 Elsevier B.V.Hundreds of millions of tons of corn straw are available each year, and its main component is crystalline cellulose, which is currently underutilized by enzyme preparations, resulting in a waste of resources. The synergistic action of lytic polysaccharide monooxygenase (LPMO) and cellulase can significantly improve the conversion efficiency of cellulose, and then generate bioenergy or other valuable chemicals. In this study, corn straw was first pretreated with steam explosion at 200 °C for 3, 6, 9 and 12 min, and its chemical composition was analyzed. It was found that the hemicellulose content gradually decreased, and the cellulose content tended to increase as the pretreatment time increased. The results on the degradation of different pretreated corn straw showed that LPMO mutant R17L (Guo et al., 2020) and cellulase had the best synergistic effect on corn straw pretreated at 200 °C for 3 min. Comparing the results of degradation of corn straw at different pH, it was found that the reducing sugar produced by the degradation of corn straw at pH 6.0 were higher than that at pH 7.0. By analyzing the synergistic effect of different doses of R17L and cellulase, the optimal enzyme cocktail was 4 mg of R17L and 0.2 mL of commercial cellulase per gram of corn straw. Finally, by analyzing the surface morphology of corn straw under different enzymatic systems, it was found that the corn straw degraded by R17L in synergy with cellulase was the most fragmented, indicating that R17L disrupted the structure of corn straw, thus providing more operable sites for cellulase to achieve efficient conversion of biomass.
查看更多>>摘要：? 2022 Elsevier B.V.Even though nanocellulose has been significantly sought after as a promising nanomaterial with great merits of biorenewability and excellent mechanical and optical properties, its preparation involves multiple steps with the utilization of strong acids or expensive enzymes, which has much hindered its commercialization. In this work, we addressed this challenge by developing a facile, green, and efficient combinatorial treatment for nanocellulose production by using phytic acid (PA) and sonication. The resultant nanocellulose had a maximum yield up to 92% when the treatment was conducted at 90 °C for 1 h, and the scanning probe microscope deciphered that the nanocellulose had a width of 22.0 ± 12.3 nm, a diameter of 5.5 ± 2.9 nm in height, and length ranged from 200 nm to 1 μm. These geometrical properties can be further improved by increasing PA pretreatment intensity. We further systematically characterized its dispersion property by using conductometric titration, Turbiscan, and Zeta potential, which indicated increased dispersion stability with the increasing pretreatment intensity. In addition, the isolated nanocellulose also shows good thermal stability over 300 °C. Overall, this acid pretreatment-assisted mechanical treatment approach greatly simplified the preparation of nanocellulose with a high yield under mild conditions.
查看更多>>摘要：? 2022 Elsevier B.V.To improve the utilization of sweet sorghum juice (SSJ) in L-lactic acid fermentation, an efficient producer of L-lactic acid with high optical purity was immobilized in the matrix including polyvinyl alcohol (PVA) and Fe3O4 magnetic nanoparticles (MNPs). In addition, the Lactobacillus rhamnosus LA-04-1 (L. rhamnosus LA-04-1) used was an invertase-active strain, and the direct conversion of sucrose which accounted for 80.14% of the total sugar from SSJ was facilitated. Fe3O4 MNPs with the size of 100 nm was obtained, and the co-immobilization of free cells and Fe3O4 MNPs was confirmed. Excellent properties of PVA/Fe3O4/LAB composite (PFLC) in mass transfer and structural stability were achieved with 10% (w/v) PVA, and stable fermentation performances were obtained within 3 freeze-thaw cycles. For batch fermentations, the productivity from SSJ was increased by 39.36% comparing with that of mixed sugars. Productivity was further increased by 3.25 times in the 12-cycle repeated-batch fermentation, during which the titer and yield of L-lactic acid reached 113.6 g L?1 and 98.97%, and the in situ separation of immobilized cells and simultaneous metabolism of fructose, glucose and sucrose were achieved. The results indicate a potential way for improving L-lactic acid fermentation by adopting PFLC and using low-cost renewable substrates.
查看更多>>摘要：? 2022 Elsevier B.V.The dynamic characteristics of the cotton stalks during the cutting process were analyzed, and the key parameters (e.g. the number of teeth, rotating speed and cutters gap) of multi-edge toothed cutting device that affect the cutting of cotton stalks were determined. Based on the designed cutting device, central composite design method and regression variance analysis method were applied to build the distributed characteristic model of the cotton stalk length in the mixture of mechanically recovered residual films and impurities after shredding, and the optimal combination of parameters was obtained. The influence law of the key parameters as well as their obvious interactions on the distribution characteristics of the cotton stalk length was analyzed, and the optimal combination of parameters of the cutting device was obtained. The average error between the physical test value and model predicted value under the same condition was 7.54%, which indicated that the test results were basically the same as the model prediction.
查看更多>>摘要：? 2022 The AuthorsHybrid composites were prepared from a polypropylene reactor blend (rPP), lignin and flax fibers. Interfacial adhesion was improved using a functionalized PP (maleated PP, MAPP) coupling agent. Composition changed in a wide range; flax content varied between 0 and 30, while lignin content between 0 and 50 vol% in 10 vol% steps. The components were homogenized in a twin-screw compounder, and injection molded specimens were prepared from the compounds for further testing. The processability of the composites was characterized by the measurement of melt flow rate, while mechanical properties by tensile and impact testing. The combination of lignin and flax fibers yields materials with an advantageous property profile, considerably decreased carbon footprint and acceptable price. The application of flax compensates for the deteriorating effect of lignin on deformability and especially on impact resistance. Significant improvement was achieved in stiffness and strength. In order to obtain this property combination, the application of a coupling agent is necessary because of the poor interaction between PP and natural reinforcements. The compounds developed may successfully compete with materials offered on the market.
查看更多>>摘要：? 2022 Elsevier B.V.This study isolated fascinating novel fungal consortium from pomelo peel (PP) to discover its potential for on-site production of lignocellulose degrading enzymes through solid-state fermentation (SSF). SSF strategy was developed to use low and high recalcitrant substrates including PP and industrial hemp residue (IHR), respectively. The result revealed that SSF using a mixture of these substrates was significantly enhanced as compared with the corresponding individual substrate. IHR was pretreated with autohydrolysis, thermal hydrolysis, and thermochemical hydrolysis. A green and sustainable catalyst, oxalic acid, was employed to further optimize the thermochemical pretreatment of IHR. Pretreatment with 3% (w/v) oxalic acid resulted the highest sugar which is 8.3 and 3.24 folds compared to autohydrolysis and thermal hydrolysis, respectively. Finally, a novel approach dubbed one-pot pretreatment and saccharification was implemented using IHR treated with 2% oxalic acid and enzymes generated by SSF of mixed substrates. This strategy resulted the highest sugar production of 39.49 g/L. The current study can be considered as a proof-of-concept for sustainable and economic production of bio-based products from waste biomass resources.
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