期刊：
Current Microbiology,2024年81(1):1-8 ISSN：0343-8651
通讯作者：
Pan, H;Pan, Hu;Tian, Y
作者机构：
[Dai, Yan-na; Pan, H; Zhang, Yi-fan; Pan, Hu; Pu, Ji-feng] Tibet Acad Agr & Anim Husb Sci, Inst Agr Qual Stand & Testing, Lhasa 850032, Peoples R China.;[Tian, Yun; Liu, Hu-hu; Tian, Y; Pan, Hu; Pan, H] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Peoples R China.;[Dai, Yan-na; Pan, H; Zhang, Yi-fan; Pan, Hu; Pu, Ji-feng] Agr & Livestock Prod Engn Technol Res Ctr Tibet Au, Lhasa 850032, Peoples R China.;[Yang, Xiao-feng] Sichuan Acad Agr Sci, Inst Agr Qual Stand & Testing Technol, Chengdu 610066, Peoples R China.
通讯机构：
[Pan, H ] T;[Tian, Y ; Pan, H] H;Tibet Acad Agr & Anim Husb Sci, Inst Agr Qual Stand & Testing, Lhasa 850032, Peoples R China.;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Peoples R China.;Agr & Livestock Prod Engn Technol Res Ctr Tibet Au, Lhasa 850032, Peoples R China.
摘要：
A novel Gram-stain-negative, aerobic, rod-shaped bacterium named T808(T) was isolated from an alpine soil in Qamdo, Tibet, PR China. Strain T808(T) grew at 5-30degree celsius, pH 5.0-9.0 (optimum, 25degree celsius and pH 7.0-8.0) with 0-2% (w/v) NaCl (optimum, 0%). The 16S rRNA gene sequences of strain T808(T) showed the highest similarity with Pararhizobium herbae CCBAU83011(T) (98.8%), followed by Pararhizobium polonicum F5.1(T) (98.7%), Pararhizobium giardinii H152(T) (98.5%), Rhizobium gei ZFJT-2( T) (98.4%), and Pararhizobium antarcticum NAQVI59(T) (97.5%). The highest digital DNA-DNA hybridization (dDDH), core-proteome average amino acid identity (cpAAI) and average nucleotide identity (ANI) values between strain T808(T) and related strains were estimated as 28.0%, 92.1% and 84.4%, respectively. Phylogenetic analysis based on 16S rRNA, core-proteome and whole-genome indicated that strain T808(T) belonged to the genus Pararhizobium. The genome size was 6.24 Mbp with genomic DNA G + C content of 60.1%. The major cellular fatty acids were Summed feature 8 (C-18:1 omega 7c or C-18:1 omega 6c), C-16:0 and C-19:0 cyclo omega 8c. The polar lipids were diphosphatidyl glycerol, phosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl choline and unidentified aminophospholipid. The isoprenoid quinone were ubiquinone-10 and ubiquinone-9. Based on phenotypic, phylogenetic, and genotypic data, strain T808(T) is considered to represent a novel species of the genus Pararhizobium, for which the name Pararhizobium qamdonense sp. nov. is proposed. The type strain is T808(T) (= JCM 36247( T) = CICC 25216( T)). According to phylogenetic coherence based on 16S rRNA, core-proteome and whole-genome, it is also proposed that the type strain Rhizobium gei Shi et al. 2016 should be reclassified as Pararhizobium gei comb. nov., the type strain is ZFJT-2( T) (= CCTCC AB 2013015( T) = KCTC 32301( T) = LMG 27603( T)).
摘要：
BACKGROUND AND PURPOSE: The P2X3 receptor, a trimeric ionotropic purinergic receptor, has emerged as a potential therapeutic target for refractory chronic cough (RCC). Nevertheless, gefapixant/AF-219, the only marketed P2X3 receptor antagonist, might lead taste disorders by modulating the human P2X2/3 (hP2X2/3) heterotrimer. Hence, in RCC drug development, compounds exhibiting strong affinity for the hP2X3 homotrimer and a weak affinity for the hP2X2/3 heterotrimer hold promise. An example of such a molecule is sivopixant/S-600918, a clinical Phase II RCC candidate with a reduced incidence of taste disturbance compared to gefapixant. Sivopixant and its analogue, (3-(4-([3-chloro-4-isopropoxyphenyl]amino)-3-(4-methylbenzyl)-2,6-dioxo-3,6-dihydro-1,3,5-triazin-1(2H)-yl)propanoic acid (DDTPA), exhibit both high affinity and high selectivity for hP2X3 homotrimers, compared with hP2X2/3 heterotrimers. The mechanism underlying the druggable site and its high selectivity remains unclear. EXPERIMENTAL APPROACH: To analyse mechanisms that distinguish this drug candidate from other inhibitors of the P2X3 receptors we used a combination of chimera construction, site covalent occupation, metadynamics, mutagenesis and whole-cell recording. KEY RESULTS: The high affinity and selectivity of sivopixant/DDTPA for hP2X3 receptors was determined by the tri-symmetric site located close to the upper vestibule. Substitution of only four amino acids inside the upper body domain of hP2X2 with those of hP2X3, enabled the hP2X2/3 heterotrimer to exhibit a similar level of apparent affinity for sivopixant/DDTPA as the hP2X3 homotrimer. CONCLUSION AND IMPLICATIONS: From the receptor-ligand recognition perspective, we have elucidated the molecular basis of novel RCC clinical candidates' cough-suppressing properties and reduced side effects, offering a promising approach to the discovery of novel drugs that specifically target P2X3 receptors.
摘要：
Recycling livestock manure in agroecosystems can maintain crop production, improve soil fertility, and reduce environmental losses. However, there has been no comprehensive assessment of synergies and trade-offs in the food-energy-soil-environment nexus under manure application. Here, we evaluate the sustainability of maize production under four fertilization regimes (mineral, mineral and manure mixed, manure, and no fertilization) from the aspect of food security, energy output, soil quality, and environmental impact based on a five-year field experiment. Manure and mineral mixed fertilization maintained grain and straw quantity and quality compared with mineral fertilization. Manure and mineral mixed fertilization increased stem/leaf ratio and field residue index by 9.1-28.9% and 4.5-17.9%, respectively. Manure also maintained the theoretical ethanol yield but reduced the straw biomass quality index by increasing ash. Further, manure application increased the soil quality index by 40.5% and reduced N(2)O emissions by 55.0% compared with mineral fertilization. Manure application showed the highest sustainability performance index of 19, followed by mineral (15), mixed (13), and without fertilization (8). In conclusion, manure application maintains food production and energy output, enhances soil quality, and reduces environmental impact, thereby improving the sustainability of maize production.
摘要：
In traditional Chinese medicine, Angelica dahurica is a valuable herb with numerous therapeutic applications for a range of ailments. There have not yet been any articles on the methodical assessment and choice of the best reference genes for A. dahurica gene expression studies. Real-time quantitative PCR (RT-qPCR) is widely employed as the predominant method for investigating gene expression. In order to ensure the precise determination of target gene expression outcomes in RT-qPCR analysis, it is imperative to employ stable reference genes. In this study, a total of 11 candidate reference genes including SAND family protein (SAND), polypyrimidine tract-binding protein (PTBP), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), TIP41-like protein (TIP41), cyclophilin 2 (CYP2), elongation factor 1 α (EF1α), ubiquitin-protein ligase 9 (UBC9), tubulin β-6 (TUB6), thioredoxin-like protein YLS8 (YLS8), and tubulin-α (TUBA) were selected from the transcriptome of A. dahurica. Subsequently, three statistical algorithms (geNorm, NormFinder, and BestKeeper) were employed to assess the stability of their expression patterns across seven distinct stimulus treatments. The outcomes obtained from these analyses were subsequently amalgamated into a comprehensive ranking using RefFinder. Additionally, one target gene, phenylalanine ammonia-lyase (PAL), was used to confirm the effectiveness of the selected reference genes. According to the findings of this study, the two most stable reference genes for normalizing the expression of genes in A. dahurica are TIP41 and UBC9. Overall, our research has determined the appropriate reference genes for RT-qPCR in A. dahurica and provides a crucial foundation for gene screening and identifying genes associated with the biosynthesis of active ingredients in A. dahurica.
摘要：
Cadmium (Cd) contamination is a widespread environmental issue. There is a lack of knowledge about the impacts of applying arbuscular mycorrhizal fungi (AMF) and biochar, either alone or in their combination, on alleviating Cd phytotoxicity in Ligustrum lucidum. Therefore, a pot experiment was conducted in a greenhouse, where L. lucidum seedlings were randomly subjected to four regimes of AMF treatments (inoculation with sterilized AMF, with Rhizophagus irregularis, Diversispora versiformis, alone or a mixture of these two fungi), and two regimes of biochar treatments (with or without rice-husk biochar), as well as three regimes of Cd treatments (0, 15, and 150mgkg(-1)), to examine the responses of growth, photosynthetic capabilities, soil enzymatic activities, nutritional concentrations, and Cd absorption of L. lucidum plants to the interactive effects of AMF, biochar, and Cd. The results demonstrated that under Cd contaminations, AMF alone significantly increased plant total dry weight, soil pH, and plant nitrogen (N) concentration by 84%, 3.2%, and 13.2%, respectively, and inhibited soil Cd transferring to plant shoot by 42.2%; biochar alone significantly enhanced net photosynthetic rate, soil pH, and soil catalase of non-mycorrhizal plants by 16.4%, 9%, and 11.9%, respectively, and reduced the soil Cd transferring to plant shoot by 44.7%; the additive effect between AMF and biochar greatly enhanced plant total dry weight by 101.9%, and reduced the soil Cd transferring to plant shoot by 51.6%. Furthermore, dual inoculation with D. versiformis and R. irregularis conferred more benefits on plants than the single fungal species did. Accordingly, amending Cd-contaminated soil with the combination of mixed-fungi inoculation and biochar application performed the best than either AMF or biochar alone. These responses may have been attributed to higher mycorrhizal colonization, soil pH, biomass accumulation, and biomass allocation to the roots, as well as photosynthetic capabilities. In conclusion, the combined use of mixed-fungi involving D. versiformis and R. irregularis and biochar addition had significant synergistic effects on enhancing plant performance and reducing Cd uptake of L. lucidum plants in Cd-contaminated soil.
摘要：
Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme -catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site -specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chem- ically diverse in terms of enzyme function and catalytic process. 2024 The Authors. Published by Elsevier B.V. on behalf of Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. This is an open access article under the CC BY -NC - ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
摘要：
The chemical structure of sinoacutine is formed by a phenanthrene nucleus and an ethylamine bridge. Because it has a similar parent structure to morphine, it is subdivided into morphinane. At present, all reports have pointed out that the basic skeleton of morphine alkaloids is salutaridine (the isomer of sinoacutine), which is generated by the phenol coupling reaction of (R)-reticuline. This study shows that the biosynthetic precursors of sinoacutine and salutaridine are different. In this paper, the sinoacutine synthetase (SinSyn) gene was cloned from Sinomenium acutum and expressed SinSyn protein. Sinoacutine was produced by SinSyn catalyzed (S)-reticuline, according to the results of enzyme-catalyzed experiments. The optical activity, nuclear magnetic resonance, and mass spectrum of sinoacutine and salutaridine were analyzed. The classification and pharmacological action of isoquinoline alkaloids were discussed. It was suggested that sinoacutine should be separated from morphinane and classified as sinomenine alkaloids.
通讯机构：
[Xue, S ] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Peoples R China.
关键词：
Perennial energy crops;Root traits;Soil organic carbon;Microbial necromass;C 4-derived carbon
摘要：
The sustainability of bioenergy cropping systems hinges on the dynamics of soil organic carbon (SOC). Switchgrass and Miscanthus, as the two leading perennial energy crops, have been extensively cultivated on marginal land for bioenergy production. However, the effects of their cultivation on SOC sequestration and its underlying mechanisms remain unclear. Herein, we quantified the contributions of plant– and microbial–derived C to SOC accumulation by tracing 13C natural abundance and amino sugars on switchgrass- and Miscanthus-planted lands (i.e. belongs to poor acidic red soil) experienced 10 years of C3–C4 vegetation conversion. The results showed Miscanthus cultivation induced an approximately 6.3 times greater improvement in SOC compared to switchgrass. However, the organic C stability in Miscanthus-planted soil was comparatively lower than that of switchgrass. This was consistent with our global meta-analysis, whereby Miscanthus and switchgrass cultivation were observed to increase SOC by 16.0% and 7.1%, respectively. Miscanthus–cultivated soil was more replenished by plant–derived C stored in particulate organic C, owing to the greater biomass and lower root quality (reflected by the high ratio of lignin to nitrogen). In contrast, switchgrass–cultivated soil was enriched with more microbial–derived C, as its greater root quality induced a more efficient C utilization by the microbes. This was preferentially associated with the soil minerals. In conclusion, perennial energy crops cultivation on marginal land substantially enhances SOC sequestration, whereas the stability of SOC is dependent on the root traits.
关键词：
Clostridium butyricum;mycelium of Phellinus igniarius;colitis;intestinal flora;serum metabolome
摘要：
Clostridium butyricum (CB) and Phellinus igniarius (PI) have anti-inflammatory, immune regulation, anti-tumor, and other functions. This study aimed to explore the therapeutic effect of CB and mycelium of PI (MPI) alone and in combination on colitis mice induced by dextran sodium sulfate (DSS). Mice were randomly assigned to five groups: (1) control (CTRL), (2) DSS, (3) CB, (4) MPI, and (5) CB + MPI (CON). The weight of the mice was recorded daily during the experiment, and the length of the colon was measured on the last day of the experiment. The colons were collected for hematoxylin and eosin staining, colon contents were collected for intestinal flora analysis, and serum was collected for metabolite analysis. The results showed that compared with the DSS group, CB, MPI, and CON treatments inhibited the weight loss and colon length shortening caused by DSS, significantly increased the concentrations of interleukin (IL)-4, IL-10, and superoxide dismutase, and significantly decreased the concentrations of IL-6, tumor necrosis factor-α, and myeloperoxidase. Gene sequence analysis of 16S rRNA showed that CB, MPI, and CON treatments changed the composition and structure of intestinal microorganisms. Metabolome results showed that CB, MPI, and CON treatments changed serum metabolites in DSS-treated mice, including dodecenoylcarnitine, L-urobilinogen, and citric acid. In conclusion, CB, MPI, and CON treatments alleviated DSS-induced colitis in mice by regulating intestinal flora and metabolites, with the CON group having the best effect.
摘要：
Nitrogen and brassinosteroids (BRs) play a vital role in modulating the growth, development, and yield of rice. However, the influences of BRs on nitrogen assimilation and metabolism in rice are not fully understood. In this study, we analyzed the impact of BRs on nitrogen utilization in rice using the indica variety 'Zhongjiazao 17' and the japonica variety 'Nipponbare' in hydroponic conditions. The results showed that BR treatment could efficiently elevate nitrate and ammonium nitrogen accumulation in both shoots and roots. Furthermore, some genes involved in the uptake of nitrate and ammonium in roots were stimulated by BRs, though we noted subtle variances between the two rice cultivars. Moreover, BRs augmented the activity of nitrate reductase (NR) and glutamine synthetase (GS) in roots, along with NR in shoots. Interestingly, BRs also spiked the total free amino acid content in both the shoots and roots. Gene expression analysis uncovered a robust induction by BRs of NR genes and GS-related genes in the roots of both 'Nipponbare' and 'Zhongjiazao 17'. Collectively, our data suggest that BRs significantly enhance the accumulation of both nitrate and ammonium in rice and trigger a series of reactions related to nitrogen utilization.
通讯机构：
[Hu, SW ] W;[Liu, G ] H;Wenzhou Med Univ, Peoples Hosp Wenling 1, Wenling Hosp, Orthopaed Ctr, Wenzhou, Zhejiang, Peoples R China.;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha, Hunan, Peoples R China.
关键词：
L. plantarum;dexamethasone;differential metabolites;food active ingredients;glucocorticoids;gut microbes;osteoporosis;probiotics
摘要：
INTRODUCTION: Osteoporosis, one of the most common non-communicable human diseases worldwide, is one of the most prevalent disease of the adult skeleton. Glucocorticoid-induced osteoporosis(GIOP) is the foremost form of secondary osteoporosis, extensively researched due to its prevalence.Probiotics constitute a primary bioactive component within numerous foods, offering promise as a potential biological intervention for preventing and treating osteoporosis. This study aimed to evaluate the beneficial effects of the probiotic Lactobacillus plantarum on bone health and its underlying mechanisms in a rat model of glucocorticoid dexamethasone-induced osteoporosis, using the osteoporosis treatment drug alendronate as a reference. METHODS: We examined the bone microstructure (Micro-CT and HE staining) and analyzed the gut microbiome and serum metabolome in rats. RESULTS AND DISCUSSION: The results revealed that L. plantarum treatment significantly restored parameters of bone microstructure, with elevated bone density, increased number and thickness of trabeculae, and decreased Tb.Sp. Gut microbiota sequencing results showed that probiotic treatment increased gut microbial diversity and the ratio of Firmicutes to Bacteroidota decreased. Beneficial bacteria abundance was significantly increased (Lachnospiraceae_NK4A136_group, Ruminococcus, UCG_005, Romboutsia, and Christensenellaceae_R_7_group), and harmful bacteria abundance was significantly decreased (Desulfovibrionaceae). According to the results of serum metabolomics, significant changes in serum metabolites occurred in different groups. These differential metabolites were predominantly enriched within the pathways of Pentose and Glucuronate Interconversions, as well as Propanoate Metabolism. Furthermore, treatment of L. plantarum significantly increased serum levels of Pyrazine and gamma-Glutamylcysteine, which were associated with inhibition of osteoclast formation and promoting osteoblast formation. Lactobacillus plantarum can protect rats from DEX-induced GIOP by mediating the "gut microbial-bone axis" promoting the production of beneficial bacteria and metabolites. Therefore L. plantarum is a potential candidate for the treatment of GIOP.
作者机构：
[Gai, Shujie; Zhou, Zhi] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Peoples R China.;[Xia, Mao; Zhang, Ye; Xia, M; Tang, Chengzhu; Gai, Shujie; Zhao, Yuanyuan; Wei, Jiaqi; Zhou, Zhi; Chen, Ke; Gao, Peixin] Hunan Opt Agr Engn Technol Res Ctr, Changsha 410128, Peoples R China.;[Xia, Mao; Zhang, Ye; Xia, M; Zhao, Yuanyuan; Wei, Jiaqi; Zhou, Zhi; Chen, Ke; Gao, Peixin] Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.;[Tang, Chengzhu; Zhou, Zhi] Hunan Agr Univ, Coll Agron, Changsha 410128, Peoples R China.;[Molokeev, Maxim S.] Univ Tyumen, World Class Res Ctr Adv Digital Technol, Tyumen 625003, Russia.
通讯机构：
[Xia, M; Zhou, Z ] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Peoples R China.;Hunan Opt Agr Engn Technol Res Ctr, Changsha 410128, Peoples R China.;Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.;Hunan Agr Univ, Coll Agron, Changsha 410128, Peoples R China.
关键词：
Bi3+-activated phosphors;full-spectrum WLED;plant fill light;quantum efficiency
摘要：
A blue‐emitting phosphor CaGdGaO4:0.005Bi3+ with high IQE of 93.7% and EQE of 70.5% is synthesized. The high thermal stability of 80.1% (@ 150 °C) is achieved. The blue and red dual‐emitting are achieved by co‐doping activators. The blue‐emitting can efficiently enhance the photosynthesis and seeding index of rice. These phosphors are promising for full‐spectrum WLED and plant fill light. Abstract Since Bi3+‐activated phosphor are widely reported in phosphors‐converted light‐emitting diodes (pc‐LEDs), developing new‐high efficiency phosphors is imperative. Herein, superior internal quantum efficiency (IQE = 93.7%) and external quantum efficiency (EQE = 70.5%) are achieved with blue‐emitting gallate phosphor CaGdGaO4:Bi3+. Particularly, the photoluminescence excitation (PLE) spectrum ranges from 200 to 400 nm with two peaks at 337 and 368 nm, which match well with the 365 nm near ultraviolet (n‐UV) chip. The blue emission is attributed to two luminescence centers caused by Bi3+ occupying GdO6 and CaO6 sites. Furthermore, the thermal stability (@ 150 °C) enhanced from 73.2% to 80.1% when Ca2+ doping. A white LED (WLED) with high color rendering index (Ra) of 93.8 is prepared by as‐synthesized phosphors, indicating the potential application in WLED. The blue and red dual‐emitting phosphors are achieved by co‐doping Bi3+ and Eu3+. Finally, the rice planting experiment presents that the blue‐emitting can efficiently enhance the photosynthesis and seeding index of rice, which indicated these phosphors have significance in plant fill light.
摘要：
Osteoporosis (OP) is a skeletal disorder characterized by decreased bone density, alterations in bone microstructure, and increased damage to the bones. As the population ages and life expectancy increases, OP has become a global epidemic, drawing attention from scientists and doctors. Because of polyphenols have favorable antioxidant and anti-allergy effects, which are regarded as potential methods to prevent angiocardipathy and OP. Polyphenols offer a promising approach to preventing and treating OP by affecting bone metabolism, reducing bone resolution, maintaining bone density, and lowering the differentiation level of osteoclasts (OC). There are multiple ways in which polyphenols affect bone metabolism. This article provides an overview of how polyphenols inhibit oxidative stress, exert antibacterial effects, and prevent the occurrence of OP. Furthermore, we will explore the regulatory mechanisms and signaling pathways implicated in this process. (c) 2023 Elsevier Inc. All rights reserved.
摘要：
BACKGROUND: Salted hen egg yolks are less oily and less flavorful than salted duck egg yolks. However, hen eggs have a more adequate market supply and have a broader application prospect than duck eggs. In this study, egg yolks, plasma, and granules were dehydrated by adding 1% NaCl to simulate traditional curing process of salted egg yolk. The changes in the pickling process of hen egg yolks (HEY) and duck egg yolks (DEY) plasma, and granules were compared to reveal the gelation mechanism and the underlying causes of quality differences in salted HEY and DEY. Salted HEY can be compared with the changes in DEY during the pickling process to provide a theoretical basis for the quality improvement of salted HEY to salted DEY. RESULTS: The results showed that both plasma and granules were involved in gel formation, but exhibited different aggregation behaviors. Based on the intermolecular forces, the HEY proteins achieved aggregation mainly through hydrophobic interactions and DEY proteins mainly through covalent binding. According to spin-spin relaxation time, HEY gels immobilized a large amount of lipid and interacted strongly with lipids. DEY gels showed much free lipid and had weak interaction with lipid. The microstructure showed that HEY proteins were easily unfolded to form a homogeneous three-dimensional gel network structure after salting, while heterogeneous aggregates were formed to hinder the gel development in DEY. Changes in protein secondary structure content showed that pickling can promote the transformation of the α-helices to β-sheets structure in HEY gels, while more α-helices structure was formed in DEY gels. CONCLUSION: The study demonstrated that different gelation behaviors of hen and duck egg yolk proteins (especially in plasma) through salting treatment led to the difference in the quality of salted HEY and DEY. This article is protected by copyright. All rights reserved.
摘要：
Hedera helix is a traditional medicinal plant. Its primary active ingredients are oleanane-type saponins, which have extensive pharmacological effects such as gastric mucosal protection, autophagy regulation actions, and antiviral properties. However, the glycosylation-modifying enzymes responsible for catalyzing oleanane-type saponin biosynthesis remain unidentified. Through transcriptome, cluster analysis, and PSPG structural domain, this study preliminarily screened four candidate UDP-glycosyltransferases (UGTs), including Unigene26859, Unigene31717, CL11391.Contig2, and CL144.Contig9. In in vitro enzymatic reactions, it has been observed that Unigene26859 (HhUGT74AG11) has the ability to facilitate the conversion of oleanolic acid, resulting in the production of oleanolic acid 28-O-glucopyranosyl ester. Moreover, HhUGT74AG11 exhibits extensive substrate hybridity and specific stereoselectivity and can transfer glycosyl donors to the C-28 site of various oleanane-type triterpenoids (hederagenin and calenduloside E) and the C-7 site of flavonoids (tectorigenin). Cluster analysis found that HhUGT74AG11 is clustered together with functionally identified genes AeUGT74AG6, CaUGT74AG2, and PgUGT74AE2, further verifying the possible reason for HhUGT74AG11 catalyzing substrate generalization. In this study, a novel glycosyltransferase, HhUGT74AG11, was characterized that plays a role in oleanane-type saponins biosynthesis in H. helix, providing a theoretical basis for the production of rare and valuable triterpenoid saponins.
摘要：
Phycocyanobilin (PCB) is a blue pigment with antioxidant, anti-inflammatory, and anticancer properties. It is used in the medical and cosmetic industries. In this study, a high-expression plasmid, pET-30a-PCB, was constructed for expression of PCB in Escherichia coli BL21(DE3). The PCB was analyzed using UV-visible absorption spectrum, MALDI-TOF-MS, and fluorescence spectra. The stability and half-life of PCB in different serum were determined. The yield of PCB was optimized through single-factor and orthogonal experiments. The optimal expression conditions were determined as a lactose concentration of 5 mmol/L, an induction time of 8 h, an induction temperature of 27 degrees C, and an induction duration of 22 h. PCB yield of 6.5 mg/L was achieved and subsequently purified using nickel-affinity chromatography. The purified PCB was quantified indirectly using Hist-tag ELISA detection, and the concentration was 11.66 mu g/L. In the range of 0-33 mu g/mL, the total antioxidant capacity and reducing the capacity of PCB were stronger than Vitamin E (Ve), with 1,1-diphenyl-2-picrylhydrazil (DPPH) scavenging reaching up to 87.07%, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) free radical (ABTS) scavenging up to 100%, hydroxyl radicals (<middle dot>OH) scavenging up to 64.19%, hydrogen peroxide (H2O2) scavenging up to 78.75%, This study provides theoretical evidence for PCB as a potent antioxidant.
摘要：
The single signal output from the tannic acid (TA) sensor can lead to false positive results. Therefore, designing the detection strategy of dual signals of colorimetric and temperature is important for accurate detection and is key to further construction of highly sensitive sensors. In this work, through a self-assembly strategy, we synthesized rosmarinic acid-cerium (RA-Ce) nanoparticles with excellent peroxidase-like activity. The RA-Ce based sensor enables fast and sensitive quantification of TA by detecting color and temperature changes with commendable linearity across the 0.05-3.5 mu M (colorimetric) and 0.1-4 mu M (temperature). The sensor demonstrated effective performance in detecting TA in different kinds of real samples. This research offers fresh insights that can inform the development of dual-signal detection strategies and the practical detection of TA. In addition, the excellent peroxidase-like activity of RA-Ce can also be used to remove pollutants.
关键词：
Cd fractionation;Microbial community;Migration and transformation
摘要：
The issue of heavy metal pollution caused by human production and living activities is progressively worsening. This study explored the effect of iron-rich organic fertilizer on the growth, quality, and cadmium (Cd) absorption of Chinese cabbage under Cd stress. The results showed that iron-rich organic fertilizer could increase the soluble protein content and root length of Chinese cabbage. Meanwhile, it could change the form of Cd to inhibit the enrichment of Cd in Chinese cabbage. The alkali hydrolyzed nitrogen (AN), total potassium (TK), organic matter (OM), and moisture content (MC) of the Z3 treatment group (2% ferrous sulfate heptahydrate) were significantly higher than those of other treatment groups. The microbial network of Z3 was more complex than the other three groups. PICRUSt analysis and correlation analysis showed that the genes related to protein synthesis (e.g., glutathione S-transferase, zinc and Cd transporter, outer membrane protein, ArsR family transcriptional regulator, catalase, etc.) can also promote microbial absorption. This study aims to provide theoretical insights into soil Cd pollution immobilization techniques.
