Food Bioscience
·
2021
·
IF 4.24
Bo Zhang,Li Chen,Jie-Yi Jin,Na Zhong,Xue Cai,Shu-Ping Zou,Hai-Yan Zhou,Zhi-Qiang Liu,Yu-Guo Zheng
: As the key precursor of coenzyme A synthesis in vivo , D-pantothenic acid plays an important role in maintaining biological function, which is widely applied in the food , pharmaceutical, and cosmetic industries. At present, it was mainly produced by chemical methods, with serious environmental pollution, therefore, it is urgent to develop an economical, practical, and environmentally friendly biological fermentation method based on microbial chassis cells. Herein, based on our previously developed D-pantothenic acid producing strains, we obtained higher yielding D-pantothenic acid producing strains by systematic metabolic engineering . First, according to the results of CRISPRi experiments, lpd were overexpressed, disrupted the non-PTS (non-phosphoenolpyruvate-pyruvate transport system) as well as enhanced the PTS (phosphoenolpyruvate-pyruvate transport system) allowing precursor accumulation. Subsequently, based on the analysis of metabolic intermediates , the pyruvate bypass pathway was blocked as well as the (R)-pantothenic acid pathway was further enhanced, increasing the titer of D-pantothenic acid to 4.60 g/L. Finally, the organic acid and branched-chain amino acid synthesis pathways were blocked, and in order to accelerate the synthesis of acetolactate and the output of D-pantothenic acid, heterologous acetolactate synthase and pantothenate transfer protein were introduced, which significantly increased the yield of D-pantothenic acid, reach to 6.33 g/L. The final strain in a 5 L bioreactor produced 32.32 g/L D-pantothenic acid with a productivity of 2.33 g/L/h and the high-yielding strain provides an effective platform for biological fermentation to produce D-pantothenic acid.
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高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Yuling Sun,Jie Liu,Zhibo Li,Jianjun Wang,Yanbin Huang
Water-soluble, biodegradable, nonionic, and biocompatible polymers with multiple functional groups are highly desired for biomedical applications. Here, we report that water-soluble nonionic poly(d/l-serine) is chirality-controllable, biodegradation-controllable, and non-cytotoxic. Hence, it can be a highly sought-after alternative to the widely used poly(ethylene glycol), with an additional advantage of having multiple hydroxyl groups for further functionalization. As one example of its biomedical applications, poly(d/l-serine) demonstrated an obvious cryoprotective effect on the red blood cells. The usage of poly(d/l-serine) in the cryopreservation field would be of great promise to resolve the difficulties in separating cryoprotectants due to toxicity.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 28
·15782-15797
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IF 4.22
Jiang Danni,Zhou Yu,Wang Ping,Huang Chao,Zhu Jian,Liu Zhiming
In the MOFs-based composites, the co-catalyst nanoparticles loads tend to agglomerate. In the self-assembly process of MOFs-based composites, the use of acid modulators solved the accumulation of AgI nanoparticles cocatalyst. The active sites of carboxyl groups and mesoporous structure brought by acid modulator provide more loading sites for AgI nanoparticles. The novel AgI/D-MIL-53(Fe) showed good adsorption and photocatalytic performance in the process of removing tetracycline pollutants. Compared to the degradation efficiency of the MIL-53(Fe) with 50.8%, it of AgI/MIL-53(Fe) increased to 85.1% and which further increased to 96.2% by AgI/D-MIL-53(Fe) based on the HCl modulator. On the one hand, it is beneficial for the mesoporous D-MIL-53(Fe) modulated by HCl modulator to disperse the AgI nanoparticles co-catalyst. On the other hand, AgI nanoparticles, as a photosensitive agent, adsorb visible light to generate photogenerated electrons and holes, and electrons rapidly transferred to the heterojunction bridge Ag 0 and then captured by the holes from the D-MIL-53(Fe). The construction of AgI/D-MIL-53(Fe) Z-scheme heterojunction provided favorable conditions for the rapid separation and photogenerated electrons and holes. Finally, ·O 2 − , ·OH and h + as the main active free radicals were driving forces. This study provided more possibilities and opportunities for the construction of mesoporous MOFs-based composites.
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Advanced Optical Materials
·
2021
·Vol. 9
·期 17
·2100622
·
IF 9.926
Yanhui Sun,Hui Li,Xiangyun Gao,Zhiyang Yu,Zhipeng Huang,Chi Zhang
The exploitation of high-performance nonlinear optical (NLO) materials is necessitated by the broad application of ultra-intensive and ultra-fast lasers. The superb nonlinear absorption and electronic-structure-related NLO response of M 3 HHTP 2 are introduced here, where M is Co(II), Ni(II), or Cu(II) and HHTP is 2,3,6,7,10,11-hexahydroxytriphenylene. With the laser excitation at 532 nm, the Cu 3 HHTP 2 exhibits a two-photon absorption (2PA) cross-section of 1.38 ± 0.11 × 10 7 GM, a value much larger than those of most reported NLO materials so far. The NLO response of M 3 HHTP 2 correlates strongly with the number of metal d electrons. With metal d electrons number increasing from 7 to 10, the optical nonlinearity of M 3 HHTP 2 under the laser excitation at 532 nm varies from three-photon absorption (3PA) in Co 3 HHTP 2 , a combination of 3PA and 2PA in Ni 3 HHTP 2 , to 2PA in Cu 3 HHTP 2 . Abundant metal d electrons can mitigate the ground-state depletion, and therefore the 2PA is enhanced. Accordingly, the superb nonlinear absorption of Cu 3 HHTP 2 can be associated with abundant d electrons in Cu.
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高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Huaxia Li,Wencui Chai,Yijun Cao,Yankun Wu,Shichong Yang
Mixed collectors were widely used in mineral flotation. In this work, D-phenylalanine (D-phe) was first introduced to improve the collectability and selectivity of sodium oleate (NaOL) for diaspore from kaolinite. The flotation performance of diaspore and kaolinite were studied by micro-flotation tests, and the synergistic mechanisms of D-phe with NaOL were investigated through FTIR spectra, zeta potential, solution chemistry and X-ray photoelectron spectroscopy (XPS). Single and mixed flotation results show that D-phe exhibited superior synergism power with the NaOL collector. Under pulp pH 9.0, the flotation recovery of diaspore was increased from 77.13% to 91.07%, while that of kaolinite was decreased from 16.27% to 13.75%. The zeta potential and XPS analysis indicate that the synergistic mechanisms of D-phe with NaOL were mainly the co-adsorption via the carboxylate group of D-phe and NaOL bonding with the Al sites of diaspore surface. D-phe was chelated onto the diaspore surface through the –COO – and –NH 3 + /NH 2 groups, and the pre-adsorption of D-phe could increase the Al active sites of diaspore surface for the direct adsorption of NaOL. NaOL could also indirectly adsorb on the diaspore surface through H-bonding with –NH 2 /NH 3 + groups of D-phe.
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高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 23
·期 3
·1382-1388
·
IF 9.48
Liang Chen,Yiming Huang,Ren Zou,Jiliang Ma,Yunyi Yang,Tingzhen Li,Mingsai Li,Qi Hao,Haibo Xie,Xinwen Peng
Synthesis of D-xylonic acid, a high value chemical feedstock, from biomass chemicals through a photocatalytic process is of great significance in respect of economical and sustainable concerns, and therefore has aroused considerable attention. Herein, a TiO2/Ti3C2(TT) photocatalyst was designed for the oxidation of xylose to D-xylonic acid under ambient conditions. The photocatalyst is fabricated by in situ growth of TiO2 nano-particles on Ti3C2 nanosheets and exhibits 64.2% of D-xylonic acid yield with excellent stability. The mechanistic study indicates that the electron transfer from TiO2 to Ti3C2 significantly increases the life time of light-induced charge carriers, and hence improved photocatalytic performance.
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高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 6
·1-6
·
IF 6.232
Zhang Xiong,Liu Qiao,Wang Zong-Wen,Xu Hui,An Feng-Ping,Huang Qun,Song Hong-Bo,Wang Yi-Wei
A fluorometric method for the determination of histamine has been developed based on aggregation-induced emission (AIE) effect of D-penicillamine capped copper nanoparticles (DPA-CuNPs). The fluorescent DPA-CuNPs were synthesized by a one-pot method using D-penicillamine as both reducing agent and stabilizing ligand. The size, morphology and physical chemical properties of DPA-CuNPs were examined by transmission electron microscopy (TEM), fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR) and absorption spectroscopy. The DPA-CuNPs exhibit AIE effect and show intense red fluorescence (650 nm). In the presence of histamine, DPA-CuNPs are dispersed into small homogeneous particles, causing fluorescence quenching. Based on this reaction, a histamine sensor is constructed. The fluorescence of the CuNPs solution has a good linear relationship with histamine concentration in the range 0.05 μM to 5 μM and the determination limit (3σ/slope) is 30 nM. The estimated method was successfully applied to the determination of histamine in fish, pork and red wine.
Schematic representation of copper nanoparticles for histamine analysis. In the presence of histamine, the strong red fluorescence of copper nanoparticles is obvious decreased through interaction of copper nanoparticles and histamine.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Teng Li,Ping Jin,Yekai Zhang,Kexin Huang,Jingen Long,Jun Jiang,Shengqin Liu,Ayusman Sen,Weiran Yang
As an important biomass-derived chemical, d-sorbitol can be converted to a variety of useful chemicals and fuels. Because of the strong nucleophilicity of I– and reducibility of hydrogen iodide (HI), hydroiodic acid has been used for polyol hydrogenolysis with high selectivity. Here, d-sorbitol was converted by HI, rhodium, and hydrogen to give a high yield of iodohexanes (94.2%) at 373 K in a water/cyclohexane biphasic system. Rhodium and hydrogen were used to regenerate HI in situ. The reaction mechanism was studied in detail by using model molecules. The substitution–elimination–addition (SEA) mechanism was proven to be the most possible pathway. The high concentration of both proton and iodide was found to be necessary for the efficient conversion of d-sorbitol and the selective formation of iodohexanes. Besides, water could inhibit the conversion of d-sorbitol dramatically. These findings were explained by kinetic study and demonstrated in the reaction kinetic equation. This catalytic system, including HI and RhCl3, was proven to be reusable. In addition, iodohexanes can be quantitatively converted to hexenes over ZrO2 at 473 K.
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高影响因子
PROCESS BIOCHEMISTRY
·
2020
·
IF 2.952
Xuelian Zhou,Yi Shen,Yong Xu,Venkatesh Balan
2-Keto- d -gluconic acid (2-KGA) is a high-value-added product from lignocellulosic straw-based biorefining process obtained via cell catalysis using Gluconobacter oxydans ( G. oxydans ); nonetheless, the economical production has some limitations because of the formation of undesirable mixture products of keto-gluconic acid from glucose. In this study, it was demonstrated that pulse addition of hydrogen peroxide (H 2 O 2 ) to synthetic media was beneficial to improve the conversion rate of glucose to 2-KGA by 1.47-fold in G. oxydans . Moreover, some lignocellulosic degradation compounds served as substitute and played the role of H 2 O 2 on corn stover hydrolysate for the production of 2-KGA. By conducting qRT-PCR analysis, eight dehydrogenase genes were identified in G. oxydans , which were responsible for regulating 2-KGA production. Moreover, most of the identified genes were found to produce membrane-bound glucose dehydrogenase and gluconate 2-dehydrogenase, and were up-regulated by adding H 2 O 2 or degradation compounds. These up-regulated genes could be responsible for directing cell catalysis of glucose to 2-KGA in G. oxydans .
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CATALYSIS LETTERS
·
2020
·Vol. 151
·期 2
·338-343
·
IF 2.482
Shi Hexian,Zhang Linfeng,Wu Yudong,Yu Rui,Peng Yang,Wang Yantao,Li Teng,Yang Weiran
Abstract Glucose and its derivatives are valuable and sustainable carbon sources that can be converted into varieties of value-added chemicals. In this study, d -glucaric acid was selectively converted to 3-iodoadipic acid (3-IAA) by hydrodeoxygenation in HI-Rh/C-H 2 system. During this process, HI was a reducing reagent, which can be regenerated in situ by metal catalyzed hydrogenation. The reaction pathway was proposed based on the intermediates identification. Under the optimal conditions, 67.2% yield of 3-IAA was obtained at 130 ℃ for 4 h. As a platform molecule, 3-IAA can be further converted to varieties of building block efficiently, such as adipic acid (AA) and 3-hydroxyadipic acid (3-HAA). Graphic Abstract
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ANALYST
·
2020
·Vol. 145
·期 20
·6579-6585
·
IF 3.978
Guanglei Lv,Yunze Xu,Jiajia Yang,Wenhui Li,Chunxia Li,Anyang Sun
Aberrant accumulation of Amyloid-β (Aβ) peptide is closely related to Alzheimer's disease. Thus, it is important to develop featured probes for the specific detection of Aβ species. Herein, we designed and synthesized a novel near-infrared fluorescent probe SDPY based on the D–π-A architecture for the detection of Aβ aggregates. The probe SDPY displayed higher affinity for Aβ40 aggregates over Aβ42 aggregates in solution (Kd = 164 nM vs. 2.1 μM). In addition, SDPY showed excellent anti-interference against a wide range of other substances. Furthermore, SDPY was capable of labeling Aβ40 aggregates better than Aβ42 aggregates in the brain sections of AD transgenic mouse models.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Yan Xia,Xiang-Mei Xiang,Kang-Yu Dong,Yan-Yan Gong,Zhan-Jun Li
Microplastics (MPs) have aroused rising social concerns. Although amounts of surfactants exist in wastewater and are expected to alter the surface properties of MPs significantly as they are designed to be adsorbed by hydrophobic particles. However, rare works have been done on the influence of surfactants on the coagulation removal process of MPs which was thought to be an effective way to remove MPs together with other natural particles, such as clay. We used 3-D fluorescence imaging to track the coagulation removal process of polystyrene MPs. Our results indicate that nonionic surfactant, tween 20 in ppm scale, could inhibit the coagulation removal of polystyrene MPs significantly. Residue MPs in the effluent is proportional with the surfactant concentration and increases up to tens of times, which will lead to a dramatic increase in their potential environmental risks. Apparent size effect exists in the coagulation in which smaller MPs can escape from the coagulation removal more easily. Mechanism study suggests that the steric resistance of the hydrophilic flexible polyethylene glycol (PEG) layer formed by tween 20 adsorbed on MP surface inhibits clay deposition and thus hinders subsequent agglomeration and precipitation. A surfactant stealth effect, which is used in the design of nanomedicine to avoid the human immune recognition and clearance of nano-drugs from blood circulation , also exists in the coagulation removal process of MPs. Our finding not only proves the strong influence of surfactants on MPs but also will stimulate related studies on other latent surfactant effects of MPs.
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高影响因子
危险品化学品经营许可证（带存储）