BIOCATALYSIS AND BIOTRANSFORMATION
·
2021
·
IF 2.181
Lu Dong,Shujuan Qi,Jianwei Jia,Yun Zhang,Yunfeng Hu
Bacillus sp. DL-1 was isolated from the deep sea of the Western Pacific Ocean and behaved very good resistance to NaCl. The extracellular proteases of Bacillus sp. DL-1 were found to exhibit excellent enantioselectivity for the kinetic resolution of (±)-1-phenylethyl acetate. To improve the stability of the enzyme, the immobilized extracellular proteases were preparated by using 60 g kieselguhr and 1-L crude fermentation broth containing extracellular proteases of Bacillus sp. DL-1, shaking at 25 °C, 200 r/min for 10 h. Every gram of kieselguhr adsorbed 25.7 mg extracellular protease and the enzymatic activity recovery was 79.86%. The immobilized proteases preserved about 35.8% of its activity after 6 repeated uses, which were also used as biocatalyst to asymmetrically hydrolyse (±)-1-phenylethyl acetate for the preparation of (R)-1-phenylethanol and (S)-1-phenylethyl acetate with high optical purities. The effects of pH, temperature, enzyme concentration, substrate concentration, reaction time and additives (metal ions/surfactants) on the resolution were investigated by single factor experiments. Under the optimal reaction conditions (10 mM (±)-1-phenylethyl acetate, 40 mg/mL immobilized extracellular proteases, pH 7.5 (Tris-HCl), 5% (v/v) methanol and 45 °C for 2 h), (R)-1-phenylethanol was generated with the e.e.p being > 97%, and the yield being 53%, respectively. Analogously, under the optimal reaction conditions (10-mM (±)-1-phenylethyl acetate, 360 mg/mL immobilized extracellular proteases, pH 6.0 (PB), 5% (v/v) DMSO and 35 °C for 1.5 h), (S)-1-phenylethyl acetate was generated with the e.e.s being over 99% and the yield being 79%, respectively. Compared with the extracellular proteases from Bacillus sp. DL-2, the immobilized extracellular proteases from Bacillus sp. DL-1 exhibited higher hydrolytic activity and could asymmetrically hydrolyse (±)-1-phenylethyl acetate by using higher substrate concentrations, shorter reaction times to obtain higher yields. Notably, the extracellular proteases of Bacillus sp. DL-1 were demonstrated to behave the same enantio-preference as those of most other reported esterases/lipases. Proteases from deep-sea Bacillus sp. DL-1 are promising biocatalysts for the synthesis of valuable chiral chemicals.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 45
·期 1
·169-178
·
IF 3.288
Lingmei Yang,Shiyou Xing,Wen Luo,Gai xiu Yang,Zhongming Wang,Pengmei Lv
Hydrogention of lipid to jet fuel especially iso-alkanes is considered as a promising technology to improve the cold-flow properties of bio-jet fuel. In this study, we successfully synthesized a hydroisomerization catalyst that is based on a SAPO-11 molecular sieve (SAPO-11-A-6) with a sea urchin-like and hierarchical porous structure. SAPO-11-A-6 was fabricated with an Al : cetyltrimethylammonium bromide (CTAB) ratio of 0.006 after pre-crystallization using an in situ seed-induced steam-assisted method (SISAC). The SAPO-11-A-6 molecular sieves exhibited abundant mesopores, a larger external surface area, and more acidic sites than SAPO-11-S molecular sieves without CTAB. After loading nickel nanoparticles by using a citric-acid-assisted impregnation method, the hydrogenation of oleic acid results indicated that among the series of Ni/SAPO-11 catalysts, a maximum of 78.2% isomer selectivity was achieved by the Ni/SAPO-11-A-6 catalyst under reaction conditions of 360 °C, 4 h, and 4.0 MPa H2. The crystal formation route of the sea urchin-like hierarchical porous SAPO-11 was proposed: after pre-crystallization, the cationic surfactant CTAB entered the layered semi-crystalline phase, contributing to the formation of the novel sea urchin-like mesoporous SAPO-11 structure.
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高影响因子
Food & Function
·
2020
·Vol. 11
·期 6
·5004-5016
·
IF 4.171
Kaixin Guo,Linnan Su,Yongchao Wang,Huihui Liu,Jing Lin,Peng Cheng,Xiquan Yin,Ming Liang,Qiangqiang Wang,Zebo Huang
Sea cucumbers have been used as food delicacies and traditional medicine for centuries, and their health benefits are partly attributed to their repertoire of proteins. Peptides prepared from the sea cucumber Apostichopus japonicus are reported to have in vitro antioxidant activities. Here, we investigated the in vivo antioxidant capacity of AjPH, a peptide-rich A. japonicus protein hydrolyzate, and found that AjPH is capable of increasing the survival rate and reducing the reactive oxygen species (ROS) level in the animal model Caenorhabditis elegans under increased oxidative stress induced by paraquat. AjPH is also shown to enhance the antioxidant defense system in paraquat-exposed nematodes, including upregulation of superoxide dismutase and catalase activities and reduction of malondialdehyde contents. To explore underpinning antioxidant mechanisms, cellular and chemical assays were used to demonstrate that AjPH not only reduces ROS accumulation in cells but also directly scavenges DPPH free radicals. Further studies indicate that AjPH can decrease age pigments and extend lifespan but does not reduce food intake, body length and brood size of the nematodes, demonstrating its capacity to delay physiological aging. Using activity-guided fractionation by ultrafiltration and gel filtration, we then isolated antioxidant fractions from AjPH and identified the sequences of their composing peptides, which were subjected to in silico analysis for prospective motifs, physicochemical properties and antioxidant potential. Taken together, our results provide an insight into the nutraceutical potential of the sea cucumber protein hydrolyzate for aging and related conditions and also a basis for future mechanistic studies of individual antioxidant peptides.
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PubMed
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 4
·1161-1170
·
IF 5.721
Huiyu Yang,Lisha Zhai,Ke Li,Xin Liu,Bo Deng,Weilin Xu
A nano-graphite-doped TiO2 composite, C-TiO2, was fabricated by atomic layer deposition (ALD) of TiO2 onto carbon fiber fabrics (CFFs), followed by calcination. The morphology and structure of the C-TiO2 composite were characterized by various techniques. The photocatalytic activity of C-TiO2 was compared with that of commercial P25. Results revealed that the nano-graphite/TiO2 “islands” with diameters of ∼5.5 nm were uniformly embedded inside the graphite “sea”. Nano-graphite sheets closely contacted with TiO2, which formed Ti–O–C bonds between nano-graphite and TiO2. The as-prepared C-TiO2 showed 2.1-fold higher photocatalytic activity than that of P25 and the reported C-TiO2 composite under visible light. C-TiO2 could effectively degrade MB at a removal rate of up to 93.1% even after 6 cycles of repeated usage.
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高影响因子
GLYCOBIOLOGY
·
2019
·Vol. 29
·期 11
·755-764
·
IF 4.194
Yan Lufeng,Li Lingyun,Li Junhui,Yu Yanlei,Liu Xinyue,Ye Xingqian,Linhardt Robert J,Chen Shiguo
Fucosylated chondroitin sulfates (FCSs) from sea cucumbers have repetitive structures that exhibit minor structural differences based on the organism from which they are recovered. A detailed characterization of FCSs and their derivatives is important to establish their structure–activity relationship in the development of new anticoagulant drugs. In the current study, online hydrophilic interaction chromatography–Fourier transform mass spectrometry (FTMS) was applied to analyze the FCS oligosaccharides generated by selective degradation from four species of sea cucumbers, Isostichopus badionotus, Pearsonothuria graeffei, Holothuria mexicana and Acaudina molpadioides. These depolymerized FCS fragments were quantified and compared using the glycomics software package, GlycReSoft. The quantified fragments mainly had trisaccharide-repeating compositions and showed significant differences in fucosylation (including its sulfation) among different species of sea cucumbers. Detailed analysis of FTMS ion peaks and top-down nuclear magnetic resonance spectroscopy of native FCS polysaccharides verified the accuracy of this method. Thus, a new structural model for FCS chains from these different sea cucumbers was defined. This bottom-up approach provides rich detailed structural analysis and provides quantitative information with high accuracy and reproducibility and should be suitable for the quality control in FCSs as well as their oligosaccharides.
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PubMed
高影响因子
Journal of Food Measurement and Characterization
·
2019
·Vol. 13
·期 4
·2790-2797
·
IF 1.415
Han Yi-Tong,Zhao Chen-Chen,Han Jia-Run,Yan Jia-Nan,Du Yi-Nan,Shang Wen-Hui,Wu Hai-Tao
The purpose of the present study was to explore the antioxidant activity of organic extracts from Maillard reaction products (MRPs) of sea cucumber ( Stichopus japonicus ) gut hydrolysates (SCGHs). The SCGHs were obtained after treatment with neutrase, and they were then reacted with ribose at a mass ratio of 1:2, pH 8.0, and 95 °C for up to 12 h. The MRPs were extracted by methanol and ethanol. The methanol extracts of the MRPs had a higher UV absorbance, browning intensity, and fluorescence intensity than the crude MRPs. The scavenging capacities of methanol and ethanol extracts from MRPs in both 2′,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assays increased significantly ( p < 0.05). The methanol extracts were better than the ethanol extracts showing the reduced IC 50 levels for ABTS and DPPH by 50% and 50%, respectively. The inhibitory activity for peroxidation of linoleic acid of MRPs was also enhanced in the methanol extracts of MRPs, but this was reduced in ethanol extracts. Moreover, HepG2 cell viability after exposure to the methanol extracts of MRPs was increased to 59.30 ± 0.43% compared with the SCGHs and MRPs, which was 3.97 times that of the H 2 O 2 -treated group. These results suggest that methanol extraction can improve the antioxidant activity of SCGHs-ribose MRPs and that the corresponding extracts can be potentially used as food antioxidants.
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高影响因子
Journal of Aquatic Food Product Technology
·
2017
·
IF 0.478
Jia-Run Han,Zhi-Mo Zhu,Hai-Tao Wu,Na Sun,Yue Tang,Cui-Ping Yu,Chen-Chen Zhao,Zheng-Yu Zhang,Ao-Ting Li,Jia-Nan Yan
Maillard reaction products (MRPs) were produced in sea cucumber gut hydrolysates (SCGHs)-ribose system at 75°C, 85°C, and 95°C with a pH value of 7.0 or 8.0 for 12 hour. The parameters of amount of intermediate products, fluorescence intensity, browning development, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability showed a positive correlation with each other in SCGHs-ribose system. The amount of intermediate products, fluorescence intensity, and browning development followed the zero-order kinetic with activation energy from 62 to 91 kJ/mol in the Maillard reaction of SCGHs-ribose system. Moreover, 2-methyl-butanal has positive and significant correlation with DPPH radical scavenging ability of SCGHs-ribose MRPs. These results suggest that Maillard reaction improves the antioxidant activity of SCGHs, which contributes to the generation of intermediate, fluorescent, browning, and volatile products of SCGHs-ribose system.
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高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xuebin Zhu,Hongyan Li,Haiming Li,Shilei Xia,Juanjuan Wang,Baolian Zhang,Dongqing Wei,Jiangang Wang
In the previous work, ceramic fiber aerogels with hollow porous structure imitating deep-sea glass sponge were reported firstly. The materials showed excellent thermal insulation and shrinkage resistance. However, the problems that have an impact on material properties had not been deeply investigated, for example, ceramic precursors and fiber surface pore structures. In this paper, different hollow porous ceramic fiber aerogels were prepared by using ceramic precursors. The mechanisms of hollow porous structures in terms of thermal and mechanical properties were investigated by means of multiscale simulations. The results indicated that the morphology and distribution of pores on the surfaces of fibers spun from various precursors exhibited significant variation. The pores on the surface of the fibers spun with polyborosilazane (PBSN) as the ceramic precursor had smaller and more uniformly dense pore sizes and were circular in shape. The thermal convection and thermal conduction were reduced by dense circular holes, and stress was effectively transferred and dispersed. The prepared hollow porous ceramic fiber aerogels displayed significantly improved thermal insulation, shrinkage resistance and mechanical properties.
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高影响因子
MARINE POLLUTION BULLETIN
·
2024
·
IF 5.3
Peng Zhang,Yaqing Cui,Ren Shi,Jing Wang,Linke Ge,Qinglin Mu
This study investigated 17 organophosphate esters (OPEs) in the surface sediments of Hangzhou Bay and the East China Sea. The mean concentration of ∑OPEs in Hangzhou Bay (235.3 ng/g) was slightly lower than that in the East China Sea (273.5 ng/g), with detected analytes dominated by Diethyl phosphate, Tris(2-chloropropyl) phosphate, and Tris(1-chloro-2-propyl) phosphate. Based on principal component analysis and cluster analysis for the source apportionment of OPEs, the results indicated that the high levels of OPEs in the East China Sea close to Yangtze River estuary can be attributed to a significant large-scale OPEs production site located along the southern Yellow Sea and the western coast of the East China Sea. Furthermore, the risk assessment conducted on aquatic organisms indicated the non-ecological risk of OPEs. However, future research should focus on the potential composite impacts of OPEs on the water systems and human health.
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PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 23
·5800
·
IF 4.2
Xiqian Tan,Xiaoqing Wang,Fangchao Cui,Ali Zeshan,Dangfeng Wang,Xuepeng Li,Jianrong Li
The sea cucumber intestine (SI), a secondary product from sea cucumber processing, contains polysaccharides as one of its active ingredients, and fermentation is an effective method for extracting bioactive substances from food by-products. In this study, to explore the effect ofEnterococcus hiraeGS22 fermentation on the extraction of SI polysaccharides, the polysaccharides were extracted through the SI with and withoutEnterococcus hiraeGS22 fermentation, and the obtained polysaccharides were designated as SC-PF and SC-P. The extraction yield, the structural characteristics, and the biological functions of the polysaccharides were then evaluated. The results indicated thatEnterococcus hiraeGS22 could grow well using SI as the substrate and that fermentation could improve the extraction yield of the polysaccharide from 0.48% to 0.63%, decrease the molecular weight (Mw), and change the monosaccharide composition. The diameter of SC-PF was smaller than SC-P, and the absolute value of the zeta potential of SC-PF was found to be lower than SC-P. Fermentation does not change the functional group or the thermal ability of the polysaccharide. SC-PF had better antioxidant ability than SC-P; the DPPH and superoxide anion scavenging ability were 96.3% and 36.5%, respectively. SC-PF also showed nearly 1.3- and 1.1-fold higher inhibition of α-glucosidase and α-amylase as compared to SC-P. The current results showed thatE. hiraeGS22 fermentation has the potential to extract SI polysaccharides with better prebiotic abilities.
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PubMed
高影响因子
Nanoscale
·
2024
·Vol. 16
·期 48
·22350-22359
·
IF 5.8
Weiping Xiao,Yue Zhang,Changwang Ke,Qin Zhao,Fengyan Han,Junpo Guo,Xiaofei Yang
Designing cost-effective and highly stable heterostructures with synergistic active sites could simultaneously catalyze the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) for (sea) water splitting. However, there are still challenges in maintaining the catalytic performance of individual materials and in constructing intimate interfaces. Herein, a novel corrosion engineering method is provided to prepare self-standing Fe2O3-Pt/NF nanoflowers where ultra-small amounts of Pt combined with Fe2O3 are in situ grown on nickel foam (NF) in the corrosion system of “H2PtCl6–NaCl–FeCl3”. The synthesized Fe2O3-Pt/NF shows the presence of a Pt–O bond, which can regulate the electronic structure of the active sites and optimize the binding energy of the reaction intermediates, leading to an improvement in catalytic performance. Compared with Pt/NF and FeOOH/NF, the Fe2O3-Pt/NF heterostructure exhibits remarkable electrocatalytic activities with overpotentials reaching 94 mV and 265 mV for the HER and OER, respectively, at a high current density of 100 mA cm−2 in alkaline solution. Furthermore, the self-assembled electrolytic cell employing Fe2O3-Pt/NF as the bifunctional electrode only requires potentials of 1.60 V and 1.61 V to achieve a current density of 100 mA cm−2 in overall water and seawater splitting, respectively. This material remained stable for 10 hours without obvious attenuation, indicating its good environmental adaptability and stability. Specifically, the enhanced catalytic activity and stability can be ascribed to the abundant active sites of nanoflowers, fast electron transfer rate of intimate interfaces, and strong electronic interaction between Pt atoms and Fe2O3. This work provides a new insight into the construction of highly efficient co-catalysts with intimate interfaces based on corrosion engineering methods.
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Fang Wu,Yuhong Jiao,Jinlong Ge,Yujun Zhu,chao feng,Zhong Wu,Chang-Peng Lv
Exploring highly active, low-cost electrocatalysts for oxygen evolution reaction (OER) is of great significance but still a major challenge. Here, we synthesized Ni(OH)2@Ni(Fe)OOH with a sea urchin structure on nickel foam via a simple hydrothermal and subsequent soaking process. Experimental results indicate that incorporation of Fe into Ni(OH)2 is favorable for modulate the electronic structure, faster electron transfer and improved intrinsic activity, thereby leading to excellent OER activity. The optimized Ni(OH)2@Ni(Fe)OOH exhibits superior OER activity with overpotentials of 245 and 310 mV at 10 and 100 mA cm-2, respectively, and a small Tafel slope of 40.7 mV dec-1, and along with high stability over 100 h, which is more active than benchmark RuO2 and sever control samples without introduction of Fe. More importantly, the overall water splitting system by using Ni(OH)2@Ni(Fe)OOH-100 as anode and Pt/C as the cathode only requires a cell voltage of 1.54 V to afford 10 mA cm-2. This work not only demonstrate the key factor of Fe doping, but also offers a new path for the development of NiFe-based OER catalysts.
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高影响因子
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