APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2023
·Vol. 107
·期 18
·5761-5774
·
IF 5
Li Jun,Chen Haiqin,Chang Lulu,Wu Chen,Zhang Hao,Chen Yong Q.,Chen Wei
Abstract Mortierella alpina produces various polyunsaturated fatty acids in the form of triacylglycerols (TAG). Diacylglycerol acyltransferase (DGAT) catalyzes the binding of acyl-CoA to diacylglycerol to form TAG and is the key enzyme involved in TAG synthesis. A variety of DGATs are present in M. alpina ; however, comparative analysis of the functional properties and substrate selectivity of these DGATs is insufficient. In this study, DGAT1 (MaDGAT1A/1B/1C) and DGAT2 (MaDGAT2A/2B) isoforms from M. alpina were analyzed and heterologously expressed in S. cerevisiae H1246. The results showed that MaDGAT1A/1B/2A/2B were able to restore TAG synthesis, and the corresponding TAG content in recombinant yeasts was 2.92 ± 0.42%, 3.62 ± 0.22%, 0.86 ± 0.34%, and 0.18 ± 0.09%, respectively. In S. cerevisiae H1246, MaDGAT1A preferred C16:1 among monounsaturated fatty acids, MaDGAT1B preferred C16:0 among saturated fatty acids (SFAs), and MaDGAT2A/2B preferred C18:0 among SFAs. Under exogenous addition of polyunsaturated fatty acids (PUFAs), MaDGAT1A and 2A preferentially assembled linoleic acid into TAG, and MaDGAT2B had substrate selectivity for eicosapentaenoic and linoleic acids in ω-6 PUFAs. In vitro, MaDGAT1A showed no obvious acyl-CoA selectivity and MaDGAT1B preferred C20:5-CoA. MaDGAT1A/1B preferred C18:1/C18:1-DAG compared with C20:4/C20:4-DAG. This study indicates that MaDGATs have the potential to be used in the production of LA/EPA-rich TAG and provide a reference for improving the production of TAGs in oleaginous fungi. Key points
• MaDGAT1A preferred C16:1 among MUFAs, MaDGAT1B and MaDGAT2A/2B preferred C16:0 and C18:0 among SFAs, respectively
• MaDGAT1A/2A preferentially assembled linoleic acid into TAG, and MaDGAT2B has substrate selectivity for eicosapentaenoic acid and linoleic acid in ω-6 PUFAs
• MaDGAT1A showed no obvious acyl-CoA selectivity, and MaDGAT1B preferred C20:5-CoA. MaDGAT1A/1B preferred to select C18:1/C18:1-DAG compared with C20:4/C20:4-DAG
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 39
·90936-90948
·
IF 5.8
Lv
Yinzhi,Chen Lin,Zhang Anning,Sheng Guodong,Liao Qing
The separation and recycling of rare earth elements (REEs) are very important owing to the high demand, limited resource, specific usages, and environmental issues. In this work, two-dimensional Ti 3 C 2 T x MXene was introduced to remove REEs (Nd(III) and La(III)) from water, and its physicochemical properties were conducted by HRTEM, SEM–EDS, XRD, FTIR, and XPS. Various parameters, such as initial pH, REEs initial concentration, contact time, and temperature, were investigated by batch experiment, respectively. Furthermore, the adsorption kinetic and isotherm were examined to analyze the adsorption behavior and adsorption mechanism. Nd(III) and La(III) have a good affinity with Ti 3 C 2 T x MXene surface functional groups (-F, -OH, and containing oxygen groups). The maximum adsorption capacities of Ti 3 C 2 T x MXene for Nd(III) and La(III) were 229.85 mg/g and 175.83 mg/g at T = 333 K, respectively. The adsorption data of Nd(III) on Ti 3 C 2 T x MXene fitted well with the Freundlich isotherms model and pseudo-second-order kinetic model. However, the best fitting for La(III) adsorption on Ti 3 C 2 T x MXene was described by both pseudo-first-order and pseudo-second-order model. Thermodynamic study of Nd(III) and La(III) adsorption on Ti 3 C 2 T x MXene showed that the reaction was a spontaneous and endothermic process. These results indicated Ti 3 C 2 T x MXene had a great potential in extracting REEs from an aqueous solution.
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FIBERS AND POLYMERS
·
2023
·Vol. 24
·期 9
·3007-3017
·
IF 2.5
Chen Yatian,He Bin,Chen Qiufei,Malik Hamza,Zhu Hongqiang,Wang Yuhang,He Jian,Ma Bomou,Wang Xueli,Zhang Hui,Liu Yong
The effects of KBrO 3 modification on polyacrylonitrile (PAN) precursor fibers at different modification temperatures were studied. The mechanical properties, chemical structure, aggregation structure, morphological structure, and thermal behavior of PAN precursor fibers were analyzed. The mechanical properties of PAN precursor fibers are essentially unaltered after KBrO 3 modification, although oxygen-containing functional groups are introduced. KBrO 3 can ionize bromate ion in aqueous solution, which has good nucleophilicity and can attack the positively charged carbon atom in C≡N, so that the cyclization proceeds according to the ionic mechanism, allowing the transformation of C≡N to C = N in the PAN precursor fibers generated a cyclic trapezoidal structure containing primary aromatic amine, which reduced the peak temperature of the cyclization reaction from 284.5 °C to 275.1 °C and decreased the heat release. The sp3-hybridized carbon structure changes into a sp2 hybridized C = C structure with increasing aromatization, according to XRD and Raman data, and the KBrO 3 alteration accelerates the degradation of the original microcrystalline structure and transforms into a new polycyclic aromatic structure. The degree of conjugation and aromatization of the system rapidly increased with the rise in modification temperature. The stabilized fibers were discovered to have the lowest R-value, the highest aromatization, the smoothest surface, and the fewest flaws at impregnation temperature of 60 °C.
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WATER AIR AND SOIL POLLUTION
·
2023
·Vol. 234
·期 8
·1-13
·
IF 2.9
You Yu,Liu Haicheng
With the increased use of microplastics and antibiotics in modern society, a large number of microplastics and antibiotics are being found in natural and water treatment systems. In this paper, the effect of polypropylene (PP), polyethylene (PE), and polystyrene (PS) microplastics (MPs) on the chlorination of ciprofloxacin (CIP) and subsequent production of disinfection byproducts (DBPs) was investigated using sodium hypochlorite (NaClO) as the disinfectant and trichloromethane (CHCl 3 ) and dichloroacetonitrile (DCAN) as typical carbon- and nitrogen-containing disinfection byproducts. Disinfection byproducts (DBPs) were investigated. The results showed that the mass concentrations of CHCl 3 and DCAN generated after CIP chlorination were higher, reaching 160.1 μg/L and 2.5 μg/L, respectively, than those generated after the chlorination of microplastics (0.49~41 μg/L). Considering the effect of microplastics on the chlorination of ciprofloxacin to generate disinfection byproducts, it was found that the increase in the production of CHCl 3 and DCAN was not significant and that production even tended to decrease. There was a slight contribution to the generation of CHCl 3 with increasing microplastic concentration. There was almost no effect on DCAN, and the generation of DCAN was even inhibited. Increases in pH, NaClO dose, and chlorination time promoted the generation of CHCl 3 , but DCAN showed a decreasing trend due to its instability and easy decomposition. This study provides a theoretical basis for understanding the generation of disinfection byproducts in water sources contaminated by microplastics and antibiotics.
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Science China-Materials
·
2023
·Vol. 66
·期 8
·3213-3222
·
IF 8.1
Wen Zihao,Meng Hong,Jiang Shengda,Tang Zhongyu,Liu Yiwen,Chu Yanhui
Developing superior oxidation resistance of high-entropy diborides is critical for extending their potential applications in harsh environments. Herein, we developed non-equimolar (Hf,Zr,Ta,W)B 2 high-entropy diborides with superior oxidation resistance by adjusting W contents for the first time. The as-fabricated (Hf 0.28 Zr 0.28 Ta 0.28 W 0.15 )B 2 samples are predicted to possess superior oxidation resistance at 1473–1773 K through the oxidation depth quantitative analysis obtained by machine learning, which is attributed to the reason that the moderate WO 3 can effectively inhibit the volatilization of B 2 O 3 . Furthermore, a four-layered structure is found in the generated product layers at 1773 K, which is due to the preferential oxidation of Hf and Zr elements at low oxygen partial pressure and the different diffusion activation energies of oxide products. The preferential oxidation of Hf and Zr elements is further demonstrated by the computational phase stability diagrams, and oxygen adsorption energies and charge transfer between oxygen atoms and different metal adsorption sites via first-principles calculations. Such superior performance endows (Hf 0.28 Zr 0.28 Ta 0.28 W 0.15 )B 2 with potential applications as ultrahigh-temperature structural materials.
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Carbon Letters
·
2023
·
IF 4.5
Li Guochun,Li Jiaxin,Yang Ziyu
This study reports the synthesis of a novel graphene/chitosan/β-cyclodextrin composite material (GO/CS/β-CD) via a one-step chemical reduction method, which combines the advantages of graphene, chitosan, and β-cyclodextrin. The morphology and structure of the composite were characterized using various techniques, such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Subsequently, sortase A (SA) was immobilized onto the GO/CS/β-CD for the detection of Staphylococcus aureus . The sensor exhibited a good linear relationship within the concentration range of 30–300 CFU/mL, with a detection limit of 12 CFU/mL. The GO/CS/β-CD composite material showed enhanced properties due to the synergistic effect of graphene, chitosan, and β-cyclodextrin. The immobilization of sortase A onto the composite material improved the sensitivity and selectivity of the sensor for the detection of S. aureus . This study presents a novel graphene/chitosan/β-cyclodextrin composite material with immobilized sortase A, demonstrating enhanced sensitivity and selectivity for the detection of Staphylococcus aureus, which has potential for the development of high-performance sensors in various fields.
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BMC PLANT BIOLOGY
·
2023
·Vol. 23
·期 1
·1-16
·
IF 5.3
Zhang Yanan,Wang Di,Li Hui,Bai Hongtong,Sun Meiyu,Shi Lei
Background Lavender (genus Lavandula, family Lamiaceae) is an aromatic plant widely grown as an ornamental plant. The chemical composition of lavender is characterized by monoterpenoids, sesquiterpenoids, and other compounds, which are primarily synthesized and stored in epidermal secretory structures called glandular trichomes (GTs). Volatile organic compounds (VOCs) are responsible for the aroma characteristics of plant oil that drive consumer preference. Aroma is usually regarded as a characteristic trait for the classification of aromatic plants. Interestingly, VOCs are synthesized and stored in GTs. Lamiaceae species such as purple perilla, peppermint, basil, thyme, and oregano usually possess two types of GTs: peltate glandular trichomes (PGTs) and capitate glandular trichomes (CGTs). But the development process of PGTs in lavender has been reported in only a few studies to date.Results In this study, we identified and quantified the VOCs in four lavender cultivars by headspace-solid phase micro extraction-gas chromatography mass spectrometry (HS–SPME–GC–MS). A total of 66 VOCs were identified in these four cultivars, the most prominent of which were linalyl acetate and linalool, and flowers were the main site of accumulation of these VOCs. Here, we examined the developmental process of PGTs, including the formation of their base, body, and apex. The apex cells contained secretory cavities, which produced VOCs. Based on the reference genome sequence of the lavender cultivar ‘Jingxun 2’, several R2R3-MYB subfamily genes related to GT formation were identified. These results will guide the engineering of GTs and molecular breeding of lavender for improving the VOC content.Conclusion sIn this study, we identified the VOCs in four lavender cultivars. We analyzed the formation of GTs, and compared the number and diameter size of PGTs among four lavender cultivars. Additionally, we identified four candidate genes belonging to the R2R3-MYB family.
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EUROPEAN JOURNAL OF NUTRITION
·
2023
·Vol. 62
·期 6
·2687-2703
·
IF 5
Zhuang Kejin,Meng Weihong,Shu Xin,Liang Defu,Wang Lidong,Zhang Dongjie
Purpose When blended, animal and plant proteins can complement each other in terms of amino acid composition and release time. In this study, we investigated whether the blended protein diet has a better feeding effect than the single protein diet, and to reveal the differences in growth and intestinal microbiota composition caused by the blended protein diet. Methods Forty Sprague Dawley (SD) rats received diets with different protein sources, including casein (C), whey protein (WP), black soybean protein (BSP), and black soybean-whey blended protein (BS-WP), for eight weeks. To investigate the effects of blended protein supplement on gut microbiota and metabolites, we performed a high throughput 16S rDNA sequencing and fecal metabolomics profiling. In addition, we determined growth and serum biochemical indices, and conducted intestinal morphology analyses. Results Compared to those in the BSP and WP groups, the daily body weight gain and feed conversion efficiency increased in the BS-WP group. Serum biochemical indices indicated that the protein utilization efficiency of the WP and BS-WP groups was relatively high, and the BS-WP blended protein diet improved the protein adoption rate. The BS-WP blended protein diet also improved intestinal tissue morphology and promoted intestinal villi development compared to the single protein diets. Furthermore, dietary protein altered the composition of gut microbiota, the gut microbial diversity of rats fed with the BS-WP diet was significantly ( P < 0.05) higher than that of the other groups. The difference in dietary protein corresponded with an alteration of fecal amino acids and their metabolites, and tryptophan and tyrosine metabolism were the key mechanisms leading to the changes in fecal microbial composition. Conclusion Dietary protein sources played an important role in the growth and development of rats by influencing intestinal metabolism and microbial composition. The BS-WP blended protein diet was more conducive to nutrient absorption than the single protein diet. Furthermore, blended protein increased the diversity of intestinal microbes and aided the establishment of intestinal barrier function.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2023
·Vol. 27
·期 10
·2593-2606
·
IF 2.5
Li Er-Mei,Zhu Li,Li Chao-Xiong,Shi Ling-Jun,Li Bing,Li Fang,Deng Ning,He Jian-Bo
Stannous sulfate is commonly used as an additive in the positive lead pastes of lead-acid batteries, but its real function and mechanism are still vague and need further study. The present work investigates the intrinsic effects of tin additives on the positive electrode performance under well-controlled experimental conditions. The tin additives are added in three ways: the SnSO 4 dissolved in 4.5 M H 2 SO 4 electrolyte, the metal Sn melted in metal Pb substrate, and the SnSO 4 mixed in homemade industrial lead pastes. A series of evolutions are clearly revealed in structure, composition, and redox activity of the positive active materials with the content of Sn. Both the SnSO 4 in the electrolyte and in the positive lead pastes have a significant inhibiting effect on the transformation between PbSO 4 and PbO 2 , leading to a decrease in the charge/discharge capacities with increasing content of SnSO 4 . A similar but weaker inhibiting effect was also found for the Sn melted in the Pb-Sn alloys. The SnSO 4 has a significant enhancement effect on the grain size of PbSO 4 /PbO 2 , which increases the resistance of the solid-phase transformation deep inside the grains during the charge/discharge. All these results do not support the use of SnSO 4 in the positive pastes of lead-acid batteries. Graphical abstract
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JOURNAL OF SOLUTION CHEMISTRY
·
2023
·Vol. 52
·期 9
·1048-1065
·
IF 1.2
Li Dan,Zheng Yingdi,Jin Yang,Li Yixin
The fundamental physical properties including density, viscosity and refractive index have been measured for binary mixtures of four fatty acid ethyl esters mixed with diethyl carbonate (DEC) over the entire composition range at temperatures T = (293.15 to 323.15) K and normal atmospheric pressure. The values of excess molar volume, viscosity deviation and refractive index deviation are calculated and the effects of temperature and composition on the variation of excess properties are discussed. All of the values of excess molar volume and refractive index deviation are observed to be positive and the values of viscosity deviation are negative. The excess or deviation properties have also been evaluated and fitted to the Redlich–Kister equation with satisfied results.
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Advanced Composites and Hybrid Materials
·
2023
·Vol. 6
·期 3
·1-12
·
IF 20.1
Dang Hui,Kong Qianqian,Winchester William,Wan Xin,Lei Yu,Zhang Haisheng,Zhao Yu,Liu Xinyu,Xu Ben Bin,Zhang Baoshan,Wang Zhe
Auricularia auricula , one of the most important edible mushrooms, is affected heavily by Trichoderma . We collected the diseased samples from the main A. auricula cultivation regions to characterize the pathogen and study the effect of Trichoderma spp. on A. auricula species. We identified one Trichoderma species, T. pleuroticola , based on the internal transcribed spacer and morphology characteristics, and two types of A. auricula strains, Heiwei 15 (HW 15) and Hei 29 (H 29), were tested in this work. The growth rate of T. pleuroticola was 3.26–3.52 times higher than that of A. auricula and advantageously competed for living space and nutrients. In confrontation culture, T. pleuroticola completely inhibited the mycelium growth of A. auricula and grew on it, resulting in a diverse impact on HW 15 and H 29. In addition, T. pleuroticola can produce metabolites with antibacterial activity. The inhibition rate of volatile metabolites to H-29 and HW 15 was 13.46% and 10.44%, and the inhibition rate of nonvolatile metabolites to H-29 and HW 15 was 36.04% and 31.49%, respectively. Further analysis showed that these antifungal activities inhibiting Auricularia auricula growth were mainly attributed to the organic compounds from T. pleuroticola , nonanal, tyrosine, beta-sitosterol, and wortmannin. In short, T. pleuroticola was a highly pathogenic fungi in the production of A. auricula . Graphical Abstract T. pleuroticola can affect the normal growth of A. auricula hypha, and its metabolites also have inhibitory effects on A. auricula hypha.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 26
·68467-68476
·
IF 5.8
Yu Kun,Guo Jiaqi,Li Bing,Guo Jianzhong
Sorption is prominent in low price, high efficiency, availability, and eco-friendliness. Organic porous materials have the characteristics of easy functionalization, diverse structure and stability, and show great potential in adsorption, energy storage, catalysis, and other fields. A mesoporous phenolic resin-type polymer (PRP) was successfully synthesized and modified by solid state reaction with maleic anhydride to prepare adsorbent (called as PRP-MAH) for sorption of Pb 2+ . The impact of reaction conditions (the pH value, reaction temperature, fresh concentration of solution, ionic strength and reaction time, etc.) was systematically studied. Characterization methods such as SEM, FTIR, and XPS indicated that the synthesized adsorbent PRP-MAH had regular morphology and good stability. The fitting of isothermal adsorption experiment data conforms to Langmuir sorption isotherm, and the sorption capacity reached 366.40 mg·g −1 at 308 K. The kinetic data were consistent with the quasi-second-order model, which indicated that the chemisorption might play the main role in the sorption process. Thermodynamic research manifested that the sorption of Pb 2+ by PRP-MAH was carried out by a spontaneous process at the study temperature. The studies show that PRP-MAH can remove Pb 2+ from water solution through ion exchange, electrostatic attraction, and surface complexation.
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