查看更多>>摘要：? 2022 The AuthorsSawtoothed grain beetles, Oryzaephilus surinamensis (Coleoptera: Silvanidae), cause severe damage to various stored products, reducing their quality and nutritional value. Several chemical pesticides have been introduced to control this pest and mitigate damage, but these pesticides also affect human health and the environment, enticing researchers to seek safer products and technology, such as plant-based products and nanotechnology. In this study, we compared the effectiveness of citronella essential oil and its nanoemulsion in controlling O. surinamensis adults. The citronella essential oil was obtained through hydrodistillation, and analyzed using gas chromatography (GC) and GC/mass spectrometry (MS based on the GC-MS analysis, the predominant compounds were citronellal (46.95%), citronellol (9.49%), linalool (9.46%), β-caryophyllene (8.39%). The particles size of the prepared nanoemulsion was 57.98 nm. The lethal concentration that causes 50% mortality (LC50) in O. surinamensis adults for the pure essential oil and its nanoemulsion was 10, 15, 20, and 25 μL/L. The nanoemulsion was more effective against both females (LC50 = 20.3 μL/L) and males (LC50 = 15.7 μL/L) than the pure essential oil (LC50 = 40.02 and 52.5 μL/L, respectively). There was a significant difference in toxicity between the pure essential oil and its nanoemulsion. In addition, there were statistically significant differences (P < 0.05) between males and females when using citronella nanoemulsion only. In conclusion, citronella nanoemulsion is effective in controlling O. surinamensis and represents a promising alternative to chemical pesticides for protecting stored products.
查看更多>>摘要：? 2022 Elsevier B.V.Biodiesel, an alternative to fossil fuel, is an important sustainable energy source and has thus received considerable attention under global energy crisis scenarios. Safflower seed oil is a good substrate for biodiesel production, however, the poor oxidative stability of safflower seed oil is one of the factors limiting the quality of biodiesel. This study aimed to optimize the safflower seed oil-based biodiesel production process and attempted to regulate the expression of the CtDof2 gene through abscisic acid to affect the safflower seed oil content, thereby improving biodiesel yield. This research optimized the preparation conditions: catalyst concentration 0.56%, molar ratio of oil to alcohol 1:6.4 and temperature 105 ℃ using response surface methodology, and the highest yield of biodiesel was 95.7 ± 0.2%. To test hypothesis that the application of abscisic acid alters safflower seed oil content via CtDof gene regulation, we expressed CtDof2 in yeast, which increased yeast oleic acid content by 27.3% and decreased stearic acid content by 20.6%. The increase in monounsaturated fatty acids predicts the improvement of biodiesel quality. Meanwhile, abscisic acid altered the fatty acid composition of safflower seed oil by regulating CtDof2, leading to an increase in the antioxidant capacity of biodiesel. This study provides new ideas for the improvement of biodiesel feedstock and the improvement of biodiesel quality in the future.
查看更多>>摘要：? 2022 Elsevier B.V.Incorporating torch ginger (Etlingera eliator Jack) inflorescence essential oil (TGIEO) in active packaging could offer protection to enhance safety and extend chicken meat's shelf life. Thus, the study's objectives were to evaluate the antioxidant, antibacterial and physicochemical activities of TGIEO incorporated into a starch-based edible film (TF) for chicken meat packaging. The films were prepared by casting method and were exposed to light absorption at 200–800 nm for the light barrier and opacity properties. The water aspects, thermal analysis by differential scanning calorimetry, antioxidant activities, antimicrobial activities, and biodegradability of the film in vegetable compost were determined. Next, the coliform count, rancidity test, and 9-point hedonic scale sensory analysis for chicken meat packed with TF were evaluated. Results shows TF with higher opacity value (3.168 ± 0.03–9.024 ± 0.09), lower water solubility (0.070 ± 0.09% - 0.095 ± 0.00%) and can withstood temperatures at < 280 °C. The diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) showed antioxidant activity at 67.36 ± 2.48% and 84.78 ± 0.57%, respectively. For antibacterial activities, TF showed positive inhibition towards pathogenic bacteria; Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella Typhi, and Escherichia coli (6.0 ± 0.01–23.0 ± 0.12 mm) and exhibited significant observation for degradation in vegetal compost after 10 days. At the end of the chilled storage period (3 °C ± 1), the chicken sample TF showed the lowest coliform count (4.98 ± 0.07 CFU/g) and thiobarbituric acid reactive substances (TBARS) value (0.212 ± 0.31 mg MDA/kg). There is no significant difference (p < 0.05) for all the chicken samples for sensory analysis and concluded that the TGIEO does not affect the organoleptic properties. Thus, the TF showed significant antibacterial and antioxidant film properties that potentially extend the quality of chicken meat during the chilled storage period.
查看更多>>摘要：? 2022 The AuthorsThe purpose of this study was to create “green” biocomposite consisting of natural components which will exhibit biocidal properties against microorganisms and would have positive effect on mechanical properties. The authors assumed that the application of natural plant compound will reduce the hydrophilicity of natural fibres. Polylactide (PLA) biocomposites containing flax (Linum usitatissimum) fibres (20 wt%) were prepared by extrusion and injection molding processes. The samples containing fibres modified with the tannic acid (TA) used as biocidal and crosslinking agent as well as the control samples (with non-modified fibres) were prepared. The TA-treatment effects on the mechanical and structural properties of the biocomposites were studied using dynamic mechanical analysis (DMA) and tensile tests, differential scanning calorimetry (DSC), and thermogravimetry (TG). The flax fibres and biocomposites were examined with scanning electron microscopy (SEM): the analysis of samples fractures was performed in order to evaluate the influence of TA modification on interfacial adhesion properties. We investigated the biocidal and wettability properties of the materials. Application of the TA-modified fibres led to the deterioration of mechanical properties. TA decreased interphase adhesion and led to plasticization of PLA phase in the biocomposite. The migration of TA into PLA matrix caused its volume plasticization which lowered stiffness of the biocomposites with modified fibres. According to the thermal studies, the higher degradation temperature (Td = 352.72 oC) of materials containing modified fibres has been noted. Moreover, the hydrophobic (Θw = 91.82) and biocidal (against Escherichia coli and Staphylococcus aureus) properties of the TA-treated biocomposites have been observed. The modification of the biocomposites plant reinforcements with a natural agent is an eco-friendly method that allows to change its properties in a safe way. However, it should be conducted with caution and consideration of the intended use of the finished material.
查看更多>>摘要：? 2022 Elsevier B.V.Cistus creticus subsp. creticus is a shrubby Mediterranean plant used since ancient times in folk medicine for the treatment of different diseases. C. creticus extracts and resin contain different types of secondary metabolites, such as terpenoids (predominantly labdane type diterpenoids), and phenylpropanoids. Growth conditions seem to influence the content of labdane-type diterpenes and flavan-3-ols in leaves of C. creticus subsp. creticus. Histochemical staining of leaves’ trichomes and comprehensive phytochemical characterization of resin, leaves and their exudates, indicated that long-stalked capitate trichomes of C. creticus subsp. creticus, grown both in vitro (IV) and in greenhouse (GH), are capable of producing bioactive oleoresin-related terpenoids and phenylpropanoids compounds. Bioactivity-guided approach was implemented in search for the major antibacterial compound in C. creticus resin against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive bacteria (Bacillus cereus and Micrococcus flavus). Bioautographic assay on TLC plates with separated components of Cistus resin extract, revealed a pronounced zone of microbial growth inhibition, corresponded to a highly active compound with Rf values of 0.45, structurally characterized and identified as ent-3β-acetoxy-13-epi-manoyl oxide. This finding opens the route for focusing on isolation and functional characterization of genes involved in the biosynthesis of ent-3β-acetoxy-13-epi-manoyl oxide and its precursor ent-3β-hydroxy-13-epi-manoyl oxide, with the aim to establish sustainable in vitro biotechnological protocols for its large-scale production in homologous and heterologous plant and microbial hosts.
查看更多>>摘要：? 2022 Elsevier B.V.Ca2+-dependent lipid-binding (CaLB) family proteins, containing C2 domain, play an important role in plant growth, development, and abiotic stress response. There has been no systematic identification of CaLB family genes in cotton (Gossypium). In this study, 196 GhCaLBs were identified and divided into five groups by phylogenetic tree analysis in Gossypium hirsutum. Gene structure and conserved protein motif analysis supported the evolutionary conservation of GhCaLBs. Whole-genome or segmental duplications contributed to the expansion of GhCaLBs. 2144 orthologous and paralogous CaLB gene pairs among four cotton species were detected. And Ka/Ks values analysis showed that CaLBs experienced strong purification selection. Numerous hormone-regulated, stress-responsive, and growth and development cis-elements were detected in the 2 kb promoter regions of GhCaLBs. Besides, transcriptome data combined with qRT-PCR analysis showed some GhCaLBs were preferentially expressed in ovule or fiber. Subcellular localization experiment revealed that GhCaLB42-GFP was located in nucleus and cell membrane, while GhCalB123-GFP was in cell membrane. Overexpressing GhCaLB42 significantly promoted the elongation and density of leaf trichomes in transgenic Arabidopsis, while GhCaLB123 overexpression inhibited the elongation of leaf trichomes. Histochemical staining experiments showed that GhCaLB123 overexpression lines could significantly increase the thickness of xylem vessels and interfascicular fibers cell wall of stem compared with WT. GhCaLB42 may positively regulate fiber elongation, and GhCaLB123 inhibited elongation but promoted secondary cell wall (SCW) thickening in fiber. Yeast two-hybrid assays indicated that GhCaLB42 protein had multiple biological functions including fiber development and abiotic stress response, and GhCaLB123 might participate in substance transport for the cellulose synthesis. GhCaLB42 and its two interaction genes GhTHi1–1 and GhCIPK9 were induced to be highly expressed under ABA treatment. These findings provide an important foundation for understanding the functions of specific cotton CaLB genes and for the effective selection of fiber development related genes.
del Amo-Mateos E.Lopez-Linares J.C.Garcia-Cubero M.T.Lucas S....
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查看更多>>摘要：? 2022 The AuthorsThe complete valorisation of sugar beet pulp (SBP) through pectooligosaccharides (POS) extraction and biobutanol production was studied. A central composite experimental design was planned to optimise the time and temperature of the hydrothermal microwave-assisted extraction. 59.7% of the POS present in the SBP were recovered, and a prehydrolysate with 31.1 g POS/L was obtained under optimal conditions (165 °C and 12 min). The prehydrolysate was further precipitated by ethanol. One-step and stepwise alcohol precipitation were evaluated. The prehydrolysate:ethanol ratio was increased from 1:1–1:3 in the stepwise precipitation, whereas a ratio of 1:2 was used in the one-step precipitation. The pectin fractions differed from each other in their chemical composition. The molecular weight of the pectin fractions ranged from 474 to 523 kDa, and the degree of esterification of all of them was higher than 50%, so they can be considered high methoxyl pectins. On the other hand, the pretreated solid enriched in glucan was subjected to enzymatic hydrolysis with cellulases and fermented by Clostridium beijerinckii, producing 8.3 g butanol/L after 48 h of fermentation (53 kg butanol/t SBP). As this research has demonstrated, SBP is a suitable feedstock for a green biorefinery approach. The fractionation of SBP by hydrothermal treatment avoids using acid and alkaline solvents and allows high POS and biobutanol production yields.
查看更多>>摘要：? 2022 Elsevier B.V.As an important agricultural residue, corn stalks have been continuously used in various industries. In this work, lignin, the by-product of xylan extraction from corn stalks, was used as a useful adsorbent for the removal of methylene blue from aqueous solutions. Lignins were precipitated from the hydrolysates of pH 3 (LG3) and 5 (LG5), hoping to explore the difference in adsorption performance between the two. Detailed discussions were performed to provide a firm evaluation of adsorption models followed by batch experiments to analyze the methylene blue adsorption performance. Results showed that the lignin obtained at pH 5 had a better adsorption capacity compared with pH 3, which was mainly caused by the difference in specific surface area. When the optimal adsorption conditions (pH: 10; temperature: 35 °C; adsorption time: 90 min) were achieved, the maximum adsorption capacity of LG5 can reach 134.3 mg/g, which was much higher than those of most unmodified lignins extracted from other biomass energy sources. Regarding the adsorption behavior, the adsorption data were fitted by pseudo-second-order kinetics model and the isotherm adsorption equilibrium followed the Langmuir model. Overall, these results indicate that lignin, the by-product of xylan extraction, offers a great potential for removing methylene blue from wastewater.
查看更多>>摘要：? 2022 Elsevier B.V.Alfa grass is one of the most abundant and renewable natural fiber resources in North Africa. In this regard, this work aimed to valorize this plant by preparing a sandwich panel composed of Alfa fiber-based core and a hybrid polymer matrix composite (jute and metallic mesh) as skin. The mechanic properties of the parts (the core, skin and whole sandwich composite) were evaluated by bending, tensile and non-destructive tests. Thanks to Alfa fiber-based core, the resulting sandwich performance was higher compared to other bio-based ones such as cork-based sandwiches but had higher density. The hybridization of the jute improves the rigidity of the skin (about 65% of Young and flexural modulus, respectively) but decries the tensile strength by about 23%. The sandwich breaking was strongly influenced by the stacking sequence of the skin, the presence of metallic mesh at the interface core/skin led to delamination, which reduces the mechanical properties of the sandwich. Overall, this sandwich could find useful application as a non-structural component in building materials (separation or roofs panels).
查看更多>>摘要：? 2022 Elsevier B.V.Lightweight composite coil springs are still limited in their practical applications by costs of raw materials, resin impregnation and eco-environmental factors. Here, we fabricated a natural bamboo coil springs (BCS) via a facile hydrothermal-molding-fixing (HMF) treatment using moso (Phyllostachys edulis) bamboo slivers (BS). The BCS was superior to plant fiber-reinforced composite springs in terms of mechanical properties, dimensional designability and costs. The BCS basically inherited the cell structure and mechanical properties from natural BS, showing massive shrinkages of parenchymal cells and the occasional inter-fiber cells cracks, as well as the partial removal of lignin and hemicellulose after HMF treatment. Moreover, the BCS showed a stiffness retention rate of 86.3% after undergoing 8000 large-deformation compression cycles, demonstrating its high structural stability. The structure-function-compositions relationships of bamboo cells will help the design and manufacturing of curved bamboo furniture and structural bamboo coil springs for cushions application.
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