NEW JOURNAL OF CHEMISTRY
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2024
·
IF 2.7
Haitao Yang,Wei Liu,Zhiyuan Sun,Lan Yao
Lignin is a crucial component of plant cell walls, supporting plant growth by providing mechanical strength, aiding water transport, and enhancing resistance to pathogens. Despite extensive research on lignin biosynthesis as a renewable resource, understanding the transport and deposition of its monomers remains challenging. In this study, a novel precursor monomer was designed, SALK (alkyne-tagged sinapyl alcohol surrogate), for tracking and localizing lignin in flax cells, aiming to explore the in vivo lignification process. First, dehydrogenation polymer (DHP) of SALK was synthesized and successfully verified its biocompatibility. After click chemistry to label fluorescent dyes, incorporation of novel lignin monomers during the polymerization process was detected and imaged successfully. The results indicated that the chemical reporter could provide detailed localization information during polymerization. It was found that lignification in the bast fibers (R) cells and fiber tracheids (FT) cells of flax was different. FT cells closer to the pith showed higher maturity and lower lignification degree. While R cells, regardless of their proximity to the pith, show a relatively consistent lignification trend. At the single-cell level, lignin deposition initiates at cell corners and the middle lamella, followed by secondary cell wall, with the highest lignin content in the secondary wall of mature cells. The results of this work reveal the potential of chemical reporters in providing detailed insights into the in vivo lignification process, advancing the technology for studying the formation and function of plant cell walls.
研究领域:
植物学
·
分子生物学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2018
·Vol. 84
·期 20
·
IF 3.633
Haiquan Yang,Xiao Lu,Jinyuan Hu,Yuan Chen,Wei Shen,Long Liu
Escherichia coli is one of the most widely used host microorganisms for recombinant protein expression and metabolic engineering, but it cannot efficiently secrete recombinant proteins to extracellular space. Here, extracellular protein secretion was enhanced in E. coli by deleting two d,d-carboxypeptidase genes (dacA and dacB, single and double deletions) to perturb the cell wall peptidoglycan network. Deletion of dacA and dacB enhanced the accumulation of intracellular soluble peptidoglycan in E. coli and affected cell morphology, resulting in a more irregular cell shape and the appearance of transparent bulges. Deletion of dacA and dacB appears to disrupt the normal rigid structure, presumably due to perturbation and destruction of the cell wall peptidoglycan network. The extracellular green fluorescent protein (GFP) fluorescence intensity of deletion mutants was increased by >2.0-fold compared with that of control cells, and that of the double deletion mutant was increased by 2.7-fold. Extracellular recombinant fibroblast growth factor receptor 2 (FGFR2) and collagen E4 secretion in deletion mutants was also enhanced compared with that in the control cells. Additionally, the extracellular recombinant amylase activity of single-deletion mutants BL21 ΔdacA pETDuet-amyk and BL21 ΔdacB pETDuet-amyk was increased 2.5- and 3.1-fold, respectively. The extracellular distribution of α-galactosidase by deletion mutants was also increased by >2.0-fold. Deletion of dacA and dacB increased outer membrane permeability, which could explain the enhanced extracellular protein secretion.IMPORTANCE Cell surface structure stabilization is important for extracellular secretion of proteins in Escherichia coli. As the main constituent of the cell wall, peptidoglycan contributes to cell structure robustness and stability. Here, we perturbed the peptidoglycan network by deleting dacA and dacB genes encoding d,d-carboxypeptidase enzymes to improve extracellular protein secretion. This new strategy could enhance the capacity of E. coli as a microbial cell factory for extracellular secretion of proteins and chemicals.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2013
·Vol. 21
·期 6
·4366-4375
·
IF 2.618
Zhang Jianying,Ni Yanyan,Ding Tengda,Zhang Chunlong
Dissolved organic matter (DOM) affects arsenite [As(III)] toxicity by altering its sorption equilibrium at the cell wall interface. A better understanding of such mechanism is of great importance to assess As(III) ecotoxicity in aquatic systems. Batch experiments were conducted to study the effects of DOM on the regulation of As(III) sorption and toxicity in the diatom Navicula sp. The influence of humic acid (HA) on As(III) toxicity was assessed by measuring algal growth, chlorophyll a , and reactive oxygen species (ROS), whereas As(III) mobility across the cell wall was estimated by determining the concentration of intracellular, cell-wall-bound, and free As(III) ions in cell media. Results showed that the effects of HA on arsenite toxicity varied depending on various combinations of As(III)-HA concentrations. EC 50 had an approximate threefold increase from 8.32 (HA-free control) to 22.39 μM (at 20 mg L −1 HA) when Navicula sp. was exposed to 1.0–100.0 μM of As(III), compared to an overall low complexation ratio of HA-As(III) in a range of 0.91–6.00 %. The cell wall-bound and intracellular arsenic content decreased by 19.8 and 20.3 %, respectively, despite the lower arsenite complexation (2.10 ± 0.16 % of the total As). Meanwhile, intracellular ROS was decreased by 12.6 % in response to 10.0 μM As(III) and 10 mg L −1 HA vs. the HA-free control. The significant contrast indicated that complexation alone could not explain the HA-induced reduction in arsenite toxicity and other factors including HA–cell surface interactions may come into play. Isotherms describing adsorption of HA to the Navicula sp. cells combined with morphological data by scanning electron microscopy revealed a protective HA floccule coating on the cell walls. Additional Fourier transform infrared spectroscopic data suggested the involvement of carboxylic groups during the adsorption of both HA and As(III) on the Navicula sp. cell surface. Collective data from this study suggest that cell wall-bound HA can moderate As(III) toxicity through the formation of a protective floccule coating occupying As(III) sorption sites and decreased effective functional groups capable of binding As(III). Our findings imply that As(III) toxicity can be alleviated due to the increased hindrance to cellular internalization of As(III) in the presence of naturally abundant DOM in water.
研究领域:
环境科学
·
生态学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Mingwei Deng,Shengwang Wang,Huagang Huang,Daihua Ye,Xizhou Zhang,Yongdong Wang,Zicheng Zheng,Tao Liu,Tingxuan Li,Haiying Yu
Hydrogen peroxide (H 2 O 2 ) is a vital signaling molecule in response to cadmium (Cd) stress in plants. However, the role of H 2 O 2 on Cd accumulation in root of different Cd-accumulating rice lines remains unclear. Exogenous H 2 O 2 and 4-hydroxy-TEMPO (H 2 O 2 scavenger) were applied to investigate the physiological and molecular mechanisms of H 2 O 2 on Cd accumulation in the root of a high Cd-accumulating rice line Lu527–8 through hydroponic experiments. Interestingly, it was found Cd concentration in the root of Lu527–8 increased significantly when exposed to exogenous H 2 O 2 , while reduced significantly when exposed to 4-hydroxy-TEMPO under Cd stress, proving the role of H 2 O 2 in regulating Cd accumulation in Lu527–8. Lu527–8 showed more Cd and H 2 O 2 accumulation in the roots, along with more Cd accumulation in cell wall and soluble fraction, than the normal rice line Lu527–4. In particular, more pectin accumulation, especially low demethylated pectin, was observed in the root of Lu527–8 when exposed to exogenous H 2 O 2 under Cd stress, resulting in more negative functional groups with greater capacity to binding Cd in the root cell wall of Lu527–8. It indicated that H 2 O 2 -induced cell wall modification and vacuolar compartmentalization contributes greatly to more Cd accumulation in the root of the high Cd-accumulating rice line.
研究领域:
植物学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2021
·
IF 9.147
Li Ding,Qiang Huang,Wenyu Xiang,Xiong Fu,Bin Zhang,Jian-Yong Wu
Intact parenchyma cells were successfully isolated from potato tuber and chemically cross-linked with 5–12 wt% sodium trimetaphosphate/sodium tripolyphosphate for investigating the effect of cross-linking on the structural characteristics and enzyme susceptibility of starch encapsulated within the cell walls. The results indicated that both starch and cell wall polysaccharides were cross-linked, and the swelling power of starch was significantly decreased with increasing degree of cross-linking. The cross-linking reaction also significantly reduced the rate and extent of starch digestion in both intact and disrupted cells after cooking. In addition, the cell-wall barrier effect on starch digestion increased with the degree of cross-linking, due probably to that limited starch swelling and pectin solubilization during cooking process partially protected cell wall integrity and thus decreased cell wall permeability. Overall, the study suggests that chemically cross-linking of cell wall polysaccharides can slow down the in vitro starch digestion of cooked potato foods .
研究领域:
食品科学
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植物生理学
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产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 17
·4201
·
IF 4.2
Wenxuan Jiang,Xiangrong Deng,Lanxian Qin,Dahai Jiang,Mengqi Lu,Kai Chen,Manqi Yang,Liangliang Zhang,Jianchun Jiang,Liming Lu
This study focused on developing an effective cell wall-breaking method forPhaffia rhodozyma, followed by utilizing subcritical fluid extraction to isolate, extract, and concentrate astaxanthin from the complex fermentation products ofP. rhodozyma. A comprehensive comparison of seven distinct methods for disrupting cell walls, including dimethyl sulfoxide treatment, lactic acid treatment, sodium hydroxide treatment,β-glucanase enzymatic digestion,β-mannanase enzymatic digestion, and a combined enzymatic treatment involving bothβ-mannanase andβ-glucanase was conducted. The results identified the lactic acid method as the most effective in disrupting the cell walls ofP. rhodozyma. The software, Design Expert, was used in the process of extracting astaxanthin from cell lysates using a subcritical extraction method. Through fitting analysis and response surface optimization analysis by Design Expert, the optimal extraction conditions were determined as follows: an extraction temperature of 41 °C, extraction frequency of two times, and extraction time of 46 min. These parameters facilitated the efficient extraction, concentration, and enrichment of astaxanthin fromP. rhodozyma, resulting in an astaxanthin concentration of 540.00 mg/L. This result can establish the foundation for its high-value applications.
研究领域:
生物技术
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食品科学
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产品关联
DOI
PubMed
高影响因子
Agronomy-Basel
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2024
·Vol. 15
·期 1
·79
·
IF 3.3
Donglan Luo,Xiaogang Wang,Tingting Mi,Jianye Chen,Liangjie Ba,Sen Cao
The objective of this study is to investigate the effects of carvacrol on the postharvest storage quality and cell wall metabolism of the ’Guichang’ kiwifruit. For this purpose, the ’Guichang’ kiwifruit is selected as the test material and treated with 0.03 mg/mL of a carvacrol solution for dipping. The storage quality and cell wall metabolism of the fruit are then evaluated under ambient conditions (20 ± 1 °C). The results indicate that treatment with carvacrol effectively reduces the postharvest respiration rate and weight loss in the kiwifruit, while preserving the levels of vitamin C (VC), soluble protein, total phenols, flavonoids, soluble solids, solid–acid ratio, and soluble pectin. Additionally, it delays the decline in the starch content and mitigates the increase in soluble sugars. Furthermore, carvacrol significantly decreases amylase activity and inhibits the elevation of polygalacturonase (PG), pectin methylesterase (PME),β-galactosidase (β-Gal), and cellulase (Cx) activity. Consequently, this treatment effectively maintains fruit firmness as well as protopectin (PP) and cellulose content at elevated levels. A correlation analysis shows that firmness is highly and negatively correlated with the cell wall degrading enzymes PG, PME, β-Gal, Cx, and α-L-Af, with R values of −0.88, −0.83, −0.98, −0.94, and −0.93, respectively. The negative correlation values for the control group are all lower than 0. In conclusion, treatment with carvacrol effectively preserves a high level of postharvest ripening quality in the kiwifruit, attenuates the metabolic processes of the cell wall, and delays fruit softening and senescence.
研究领域:
植物生理学
·
食品科学
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2015
·
IF 2.002
Xiaolong Li,Congcong Ding,Jiali Liao,Liang Du,Qun Sun,Jijun Yang,Yuanyou Yang,Dong Zhang,Jun Tang,Ning Liu
The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3, isolated from a potential disposal site for (ultra-)low uraniferous radioactive waste in Southwest China, were evaluated by using transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), proton induced X-ray emission (PIXE) and enhanced proton backscattering spectrometry (EPBS). Approximately 60% of total uranium at an initial concentration of 10 mg/L uranium nitrate solution could be absorbed on 100 mg S. sporoverrucosus dwc-3 with an adsorption capacity of more than 3.0 mg/g (wet weight) after 12 hr at room temperature at pH 3.0. The dynamic biosorption process of S. sporoverrucosus dwc-3 for uranyl ions was well described by a pseudo second-order model. S. sporoverrucosus dwc-3 could accumulate uranium on cell walls and within the cell, as revealed by SEM and TEM analysis as well as EDX spectra. XPS and FT-IR analysis further suggested that the absorbed uranium was bound to amino, phosphate and carboxyl groups of the cells. Additionally, PIXE and EPBS results confirmed that ion exchange also contributed to the adsorption process of uranium.
研究领域:
微生物学
·
环境科学
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DOI
PubMed
高影响因子
Food & Function
·
2019
·Vol. 10
·期 9
·5312-5322
·
IF 3.241
Li Ding,Qiang Huang,Haiteng Li,Zhigang Wang,Xiong Fu,Bin Zhang
Modulation of the starch digestion rate and extent is a major target for increasing nutritional value of potato-based food. In order to understand the effect of controlled gelatinization on the structure and in vitro digestion properties of whole potato food, intact parenchyma cells were isolated as a model through soaking in mild acid and alkali solutions, and then hydrothermally treated at different incubation temperatures in excess water. The morphological and structural changes of entrapped starch granules as well as in vitro starch digestion properties were investigated. Three classes of starch digestion of potato cells are identified: (1) when the temperature of hydrothermal treatment was set at 55 °C or 60 °C, the efficient physical barrier of intact cell walls resulted in a limited starch digestion extent; (2) when the temperature is set at 65 °C, the cell wall structures apparently reduced the digestion rate but only slightly reduced the final extent compared to the starch counterpart, probably because starch swelling weakens the physical barrier; (3) at 70–95 °C, the damaged cell wall still reduced the digestion rate but did not reduce the digestion extent compared to the starch counterpart. The results suggest that controlling hydrothermal processing temperature is a viable approach to develop potato ingredients with enhanced nutritional functionality.
研究领域:
食品科学
·
植物生理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2019
·Vol. 56
·期 4
·2326-2331
·
IF 1.85
Zhang Zhuo,Li Min,Wu Caie,Peng Bangzhu
Patulin (PAT), a mycotoxin mainly produced by various species of fungi, is frequently detected in moldy fruit- and vegetable-based products, which pose a health risk to the consumer. Over the past decades, a few studies reported that PAT content could be significantly decreased by microbial fermentation process. However, the physical adsorption mechanism between PAT and yeast during fermentation is still unclear. In this paper, we focused on the physical adsorption of PAT by Saccharomyces cerevisiae CCTCC 93161 during fermentation in aqueous solutions. Firstly, morphology of differently treated yeast cells were analyzed by scanning electron microscope, then the interactions between PAT and yeast cells were investigated by infrared absorption spectra of differently treated S. Cerevisiae cells before and after the adsorption of PAT. The results showed that the efficiency of PAT removal raised significantly with the increase of fermentation temperature and time, whereas it decreased significantly with the increase of initial PAT concentration in the fermentation system. The proteins and polysaccharides in the cell walls of yeast interacted with PAT and accounted for the physical adsorption. The current work would possibly provide some new insights on PAT control for fermented foods.
研究领域:
食品科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 3.978
Yi Zhang,Xihui Kang,Feng Zhen,Zhongming Wang,Xiaoying Kong,Yongming Sun
Enzymatic hydrolysis is emerging as a promising unconventional pretreatment method for disrupting microalgae cells. However, the sustainability of biological enzyme needs to be improved due to low efficiency of enzymatic hydrolysis with single enzyme. Cellulase , xylanase , pectinase , snailase, lysozyme and trypsin were selected to pretreat microalgae Scenedesmus sp. for lipid extraction. The results shown that the pretreatment of a multi-enzyme combination of cellulase, xylanase and pectinase perform a better enzymatic hydrolysis effect than each single enzyme. Results shown that different sequences of enzymatic hydrolysis had a significant effect on the lipid extraction performance from microalgae, the lipid recovery yield of 100% (total lipids content) could be achieved with the sequence of stepwise enzymatic hydrolysis: pectinase (10 mg g -1 dry weight microalgae), cellulase (20 mg g -1 ) and xylanase (14 mg g -1 ). The SEM image, FTIR measurement, HPLC and XPS analysis indicated that the outer layer of trilaminar sheaths in the microaglal cell walls was first degraded by pectinase, and then cellulose and hemicellulose in the inner layer were destroyed by cellulase and xylanase. This study provides an efficient and environmental-friendly route for lipid extraction as a new strategy of enzymatic hydrolysis to valorize high-value added products in microalgae downstream processing .
研究领域:
生物技术
·
可再生能源
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产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 8
·1861
·
IF 5
Jihang Hu,Xiaoqing Wang
As the only renewable resource among the four basic materials (steel, cement, plastic, wood), wood itself and wood products have a “low carbon” value and play an important role in storing carbon. The moisture absorption and expansion properties of wood limit its application scope and shorten its service life. To enhance the mechanical and physical properties of fast-growing poplars, an eco-friendly modification procedure has been used. This was accomplished by the in situ modification of wood cell walls by vacuum pressure impregnation with a reaction of water-soluble 2-hydroxyethyl methacrylate (HEMA) and N,N’-methylenebis(acrylamide) (MBA). The anti-swelling efficiency of HEMA/MBA-treated wood was improved (up to 61.13%), whereas HEMA/MBA-treated wood presented a lower weight-gain rate (WG) and water-absorption rate (WAR). It was observed that the modulus of elasticity, hardness, density, and other properties of modified wood had improved significantly, as indicated by XRD analysis. Modifiers diffuse primarily within cell walls and cell interstices of wood, causing crosslinks between the modifiers and the cell walls, reducing its hydroxyl content and blocking the channels for water movement, thereby enhancing its physical properties. This result can be obtained by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX), Nitrogen adsorption test imaging ATR-FTIR (Attenuated total reflection-Fourier-Transform Infrared) Spectroscopy, and nuclear magnetic resonance (NMR) and Nitrogen adsorption test. Overall, this straightforward, high-performance modification method is crucial for maximizing wood’s efficiency and the sustainable development of human society.Keywords:wood modification;reaction mechanism;cell walls;grafting;properties
研究领域:
林业科学
·
材料科学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）