Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are res...Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are responsible for the formation of microbial aggregates. In this work, we successfully separated and characterized EP from EPS of the bacterium Bacillus megaterium TF10. Extraction of EP from EPS was optimized using Sevag＇s reagent. Chemical characteristics, functional groups, and molecular weight（MW） distribution of EP were compared with the harvested EPS and soluble microbial products（SMP）. We found that the polymers of lower MW and free proteins were successfully removed by Sevag＇s reagent. The higher MW components of EPS were predominantly polysaccharides,while the polymers of lower MW tended to secrete to the supernatant and were described as SMP. A part of the proteins in the EP was polysaccharide-bonded. Our results can be further used in elucidating the complex flocculation mechanisms in which EP play a major role.展开更多
Amomum villosum,Aquilaria sinensis,Morinda officinalis,and Pogostemon cablin are well-known medicinal plants in South China for their particular pharmacological activities,but their endophytic fungi have been rarely r...Amomum villosum,Aquilaria sinensis,Morinda officinalis,and Pogostemon cablin are well-known medicinal plants in South China for their particular pharmacological activities,but their endophytic fungi have been rarely reported.Here,the endophytic fungal communities associated with the leaves,stems,and roots of the four medicinal plant species were investigated by high-throughput sequencing technology.From the four medicinal plant species,a total of 169,149 sequences(reads)of endophytic fungi were harvested and clustered into 791 operational taxonomic units(OTUs)assigned to the Kingdom Fungi.These OTUs taxonomically spanned five phyla,27 classes,75 orders,167 families,and 291 genera.At the genus level,Phyllosticta,Candida,Zasmidium,and Cryptococcus were the major genera detected in A.villosum;Nigrospora,Tylopilus,Arthrobotrys,Coniosporium,and Corynespora were the dominant genera isolated in A.sinensis;Ochroconis,Cercospora,Aspergillus,and Cyphellophora were the dominant genera detected in M.officinalis;and Cladophialophora,Meira,Sakaguchia,and Penicillium were the major genera isolated in P.cablin.Among the four medicinal plant species,M.officinalis had the highest endophytic fungal diversity(H′>4.25),however A.sinensis had the lowest(H′<2.37).There were significant differences in endophytic fungal communities among different organs in the same plant species.展开更多
Two unusual sesquiterpenoids,irpexlactones A(1)and B(2),were isolated from cultures of the basidiomycete Irpex lacteus.Their structures were established by means of spectroscopic methods,the single crystal X-ray diffr...Two unusual sesquiterpenoids,irpexlactones A(1)and B(2),were isolated from cultures of the basidiomycete Irpex lacteus.Their structures were established by means of spectroscopic methods,the single crystal X-ray diffraction,as well as electronic circular dichroism(ECD)calculations.They possess a novel carbon skeleton with a 5/6/3-fused ring system that may derive from tremulane type sesquiterpenoids with ring-rearrangement.Both compounds show significant inhibitory activities against nitric oxide production with half maximal inhibitory concentration(IC50)values of 2.2 and 1.4μmol/L,respectively.Their anti-inflammatory effects were further evaluated by enzyme-linked immunosorbent assay(ELISA)and Western blot.展开更多
Hypersaline mariculture wastewater necessitates treatment prior to its discharge into marine environments.Algal-mycelial pellets(AMPs),known for their cost-effectiveness,energy efficiency and sustainability,have not b...Hypersaline mariculture wastewater necessitates treatment prior to its discharge into marine environments.Algal-mycelial pellets(AMPs),known for their cost-effectiveness,energy efficiency and sustainability,have not been previously explored for their flocculation and pollutant removal capabilities in hyperhaline conditions.This work employed an orthogonal test design to investigate the effects of nine factors at three levels on the treatment efficiency of mariculture wastewater using Chlorella sp.TNBR1 and Aspergillus niger AMPs.The comprehensive optimal conditions for achieving the highest flocculation efficiency and pollutant removal are determined to be a temperature of 30℃,light intensity of 6000 lux,a 12:0 light-dark cycle,an initial pH of 6,amicroalgal density of 11.25×10^(6)cell/mL,microalgal growth phase at the early logarithmic stage,a fungal spore density of 9.00×10^(5)spore/mL and a fungal pellet phase of 60 h.Under such conditions,the treatment of nonsterile actual mariculture wastewater with Chlorella sp.TNBR1 and Aspergillus niger AMPs results in a 93.35%±7.20%reduction in chemical oxygen demand(COD),92.83%±7.29%reduction in total nitrogen(TN),100%removal of total phosphorus(TP),and a flocculation efficiency of 69.21%±5.36%.These findings confirm that AMPs are a viable solution for effectively treating COD,TN and TP in real hypersaline mariculture wastewater,while also facilitating the flocculation and harvesting of microalgae.展开更多
Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridiza...Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.展开更多
BACKGROUND Choledocholithiasis is a severe disorder that affects a significant portion of the world’s population.Treatment using endoscopic sphincterotomy(EST)has become widespread;however,recurrence post-EST is rela...BACKGROUND Choledocholithiasis is a severe disorder that affects a significant portion of the world’s population.Treatment using endoscopic sphincterotomy(EST)has become widespread;however,recurrence post-EST is relatively common.The bile microbiome has a profound influence on the recurrence of choledocholithiasis in patients after EST;however,the key pathogens and their functions in the biliary tract remain unclear.AIM To investigate the biliary microbial characteristics of patients with recurrent choledocholithiasis post-EST,using next-generation sequencing.METHODS This cohort study included 43 patients,who presented with choledocholithiasis at the Guangdong Second Provincial General Hospital between May and June 2020.The patients had undergone EST or endoscopic papillary balloon dilation and were followed up for over a year.They were divided into either the stable or recurrent groups.We collected bile samples and extracted microbial DNA for analysis through next-generation sequencing.Resulting sequences were analyzed for core microbiome and statistical differences between the diagnosis groups;they were examined using the Kyoto Encyclopedia of Genes and Genomes pathway hierarchy level using analysis of variance.Correlation between the key genera and metabolic pathways in bile,were analyzed using Pearson’s correlation test.RESULTS The results revealed distinct clustering of biliary microbiota in recurrent choledocholithiasis.Higher relative abundances(RAs)of Fusobacterium and Neisseria(56.61%±14.81%vs 3.47%±1.10%,8.95%±3.42%vs 0.69%±0.32%,respectively)and the absence of Lactobacillus were observed in the bile of patients with recurrent disease,compared to that in stable patients.Construction of a microbiological co-occurrence network revealed a mutual relationship among Fusobacterium,Neisseria,and Leptotrichia,and an antagonistic relationship among Lactobacillales,Fusobacteriales,and Clostridiales.Functional prediction of biliary microbiome revealed that the loss of transcription and metabolic abilities may lead to recurrent choledocholithiasis.Furthermore,the prediction model based on the RA of Lactobacillales in the bile was effective in identifying the risk of recurrent choledocholithiasis(P=0.03).CONCLUSION We demonstrated differences in the bile microbiome of patients with recurrent choledocholithiasis compared to that in patients with stable disease,thereby adding to the current knowledge on its microbiologic etiology.展开更多
Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,and necrotizing enterocolitis in neonates and infants,with neurological sequelae in severe cases.Interest in ...Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,and necrotizing enterocolitis in neonates and infants,with neurological sequelae in severe cases.Interest in Cronobacter has increased significantly in recent years due to its high virulence in children.In this review,we summarize the current understanding of the prevalence of Cronobacter species in several important food types.We discuss the response mechanisms enabling persistence in adverse growth con-ditions,as well as its pathogenicity.We emphasize the food safety concerns caused by Cronobacter and subsequent control methods and clinical treatments.展开更多
Synthesis of structurally controlled graphene materials is critical for realizing their practical applications.The electrochemical exfoliation of graphite has emerged as a simple method to produce graphene materials.T...Synthesis of structurally controlled graphene materials is critical for realizing their practical applications.The electrochemical exfoliation of graphite has emerged as a simple method to produce graphene materials.This review examines research progress in the last 5 years,from 2015 to 2019.Graphene material synthesis methods generally have a trade‐off between increasing production yield and achieving better material property control.The synthesis conditions for synthesizing pristine graphene,graphene oxide(GO),and graphene composites are significantly different.Thus,in this review,we first discuss synthesis methods for graphene materials with high C/O ratios from four aspects:graphite electrodes,equipment engineering,electrolytes,and additional reduction methods.Next,we survey synthesis methods for GO and examine how the pretreatment of the graphite electrodes,electrolytes,and operation parameters,such as applied voltages,electrolyte temperatures,and mechanical forces,affect the quality of GO.Further,we summarize electrochemical exfoliation methods used to dope graphene materials,introduce covalent functional groups,incorporate various nanoparticles,and assembly of graphene architectures.For all synthesis methods,we compare the properties of resulting graphene materials such as C/O ratios,lateral size,layer numbers,and quality characterized by Raman spectroscopy.Lastly,we propose our perspectives on further research.We hope this review stimulates more studies to realize the on‐demand production of graphene materials with desired properties using electrochemical exfoliation methods.展开更多
Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensiv...Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensive spectroscopic analyses, X-ray diffraction and quantum molecular calculation. Their plausible biogenetic pathway featured an intriguing carbonyl-ene cyclization. Lithocarpinol A exhibited moderate inhibitory effect against HepG-2 and A549 tumor cell lines with IC_(50) values of 9.4 μmol/L and10.9 μmol/L,respectively.展开更多
Gastric ulcer is a widespread disease caused by various etiologies.Dendrobium offi cinale flowers exert several health benefits owing to their rich flavonoid content.In this study,protective effects and possible actio...Gastric ulcer is a widespread disease caused by various etiologies.Dendrobium offi cinale flowers exert several health benefits owing to their rich flavonoid content.In this study,protective effects and possible action mechanisms of D.offi cinale flowers’flavonoid enriched extract(DOFF)were assessed against gastric ulcer.The result of sodium nitrite-aluminum nitrate colorimetry showed that 52.34%of the total extractive was flavonoid,and ultra-high performance liquid chromatography time of flight mass spectrometer(UPLC-QTOF/MS)revealed the presence of 28 components in DOFF of which 14 belonged to flavonoids.In addition,in vivo assay revealed DOFF potential in reducing the formation of ethanol-induced gastric mucosal lesions,with drop-in ulcer index from 64.33±8.76 to 32.00±4.47.Similar results were revealed in human gastric mucosal epithelia cells,with cells viability to increase from 27.2%to 61.6%post DOFF administration.To analyzed the protect effect of DOFF,we used Western blotting and immunofluorometric assay to revealed the expression levels of key proteins in cell pathways.The results showed that DOFF(320μg/mL)could increase the level of oxidation marker protein(HO-1),apoptosis regulatory protein(Bcl-2)and autophagy marker(LC3β)by 50.84%,43.85%,and 59.21%compared with ethanol-treated group respectively.Further analyzed of the mitochondrial activity and apoptosis pathway,we found that DOFF appeared to mitigate against ethanolinduced gastric mucosal injury via AMPK/mTOR/ULK1 and PI3K/AKT autophagy signaling pathways.展开更多
Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to dr...Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.展开更多
Root-associated bacteria play a vital role in the growth and adaptation of host plants to drought stress.These bacteria can be classified as rhizoplane and rhizosphere bacteria based on their distance from the root su...Root-associated bacteria play a vital role in the growth and adaptation of host plants to drought stress.These bacteria can be classified as rhizoplane and rhizosphere bacteria based on their distance from the root surface.Tomato plants are often exposed to periodic drought and nitrogen(N)addition throughout their life cycle,but the impacts of these factors on the plant and root-associated bacteria are not well understood.To gain insight into this relationship,we conducted an experiment to monitor the effects of periodic drought and N addition on rhizoplane and rhizosphere bacteria of tomato plants.Drought and N addition had interactive effects on plant and soil properties,which varied with the timing of drought.There were clear divergences in community traits such as alpha diversity,beta diversity,and network topological features between the two types of bacteria.The rhizoplane bacteria showed lower alpha diversity but higher beta diversity and were more sensitive to drought and N addition than the rhizosphere bacteria.Nitrogen addition could downsize the effects of drought on rhizoplane bacterial community compositions.The higher proximity to the root might induce a community to develop more cooperation between different members to cope with plant metabolites,as revealed by the more connected and modularized community network of the rhizoplane bacteria.Drought at the seedling stage had great legacy effects on plant and soil properties.It may enhance selection,cause the dominance of deterministic processes in the assembly of rhizoplane bacteria,and reduce bacterial community network complexity.In conclusion,N addition could interact with drought in affecting tomato plants and their root-associated bacteria,depending on the timing of drought and the fineness of root niches.The higher sensitivity of rhizoplane bacteria to drought and N addition calls for more research due to their higher proximity and importance to plants in future environmental changes.展开更多
Selenopeptides may be a valuable bioactive compound to promote gut microbiota-targeted therapeutic methods for intestinal disease and hepatopathy.However,limited information is available on the utilization of selenope...Selenopeptides may be a valuable bioactive compound to promote gut microbiota-targeted therapeutic methods for intestinal disease and hepatopathy.However,limited information is available on the utilization of selenopeptides by gut microbiota,especially Selenium(Se)function.For this purpose,the present study aimed to investigate the protective effect of selenopeptide(RYNA(Se)MNDYT,Se-P2,purity of≥95%)and its original peptide(RYNAMNDYT,P2,purity of≥95%)in vivo by the microbiota-metabolite axis and further analyze the potential contribution of Se biofortification to Se-P2 bioactivity.The results showed that Se-P2 exhibits a higher protective effect on lipopolysaccharide(LPS)-induced inflammation than P2,including pathology of the colon and liver,which suggested that the bioactivity of P2 was promoted by the organic combination of Se.Notably,gut microbiota composition tended to be a healthy structure by Se-P2 pretreatment in LPS-injured mice,which had a positive effect on LPS-induced gut microbiota dysbacteriosis.Additionally,only Se-P2 promoted an increase in the relative abundance of Lactobacillus,Alistipes,and Roseburia and a decrease in the relative abundance of Akkermansia,Erysipelatoclostridium,and Bacteroides in LPS-injured mice.The changes in gut microbiota were obviously correlated with the changes in metabolites and affected the metabolic pathways of valine,leucine,isoleucine,phenylalanine,tyrosine,and tryptophan biosynthesis and phenylalanine metabolism.This may be one of the key reasons for Se-P2 to exert bioactivity through the microbiota-metabolite axis.Furthermore,Se-biofortification in Se-enriched Cordyceps militaris affected the parental proteins of Se-P2 to modulate mitogen-activated protein kinase,GPI anchored protein,and carbohydrate metabolism,translation,folding,sorting and degradation,which may contribute to the bioactivity of Se-P2.Our study provides information on the effect of Se on selenopeptides in vivo,which further promotes the prospective applications of selenopeptides as dietary supplements.展开更多
Since the azo dyes widely used in textile-dyeing industry are toxic, highly persistent, and ubiquitously distributed in the environment, their treatment efficiencies and fade in ecosystems have received worldwide atte...Since the azo dyes widely used in textile-dyeing industry are toxic, highly persistent, and ubiquitously distributed in the environment, their treatment efficiencies and fade in ecosystems have received worldwide attention. Due to the microbes play important roles in azo-dye degradation, exogenous nutrient addition is used as a promising biostimulation strategy to improve the treatment efficiencies of azo-dye wastewater. However, little is known about the effects of different kinds of exogenous nutrients on the azo-dye wastewater treatment directly. Here, three kinds of common nutrients, glucose, starch and yeast extract, were added to the sequencing batch reactors （SBR） for the treatment of wastewater containing acid red 73 to compare the biostimulation efficiencies by investigating the dye＇s removal efficiencies and the changes of related water qualities. Our results showed that the reactors added yeast extract had highest removal efficiencies and chemical oxygen demand （COD） as well, followed by glucose and starch. The removal rates of acid red 73 and COD were 90.63% and 8713% in the reactors added yeast extract, respectively, while 86.49% and 78.4% in those with glucose and 85.38% and 75.2% in those with starch. This study provided some useful information for the biostimulation strategy of azo-dye wastewater treatment and preliminarily suggested that yeast extract would be the optimal choice.展开更多
Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacill...Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.展开更多
In the food industry,bacterial cells usually adhere to equipment surfaces,forming biofilms that may cause persistent contamination.This study aimed to identify the key genes responsible for the stronger biofilm-formin...In the food industry,bacterial cells usually adhere to equipment surfaces,forming biofilms that may cause persistent contamination.This study aimed to identify the key genes responsible for the stronger biofilm-forming capability of the Listeria monocytogenes LMB33426 strain compared to that of the L.monocytogenes CICC 21662 strain through comparative genomics.Additionally,the expression of genes and related metabolic pathways of LMB 33426 and CICC 21662 strains were analyzed at the transcriptional level by high-throughput sequencing technology to uncover key differentially expressed genes between planktonic and biofilm cells of those two strains.Subsequently,the key genes found to present differences that were uncovered by those genome-wide and transcriptomic analyses were used to construct gene deletion strains.The crystalline violet assay and motility assay showed that GL002291,GL002712 and Imo1438 genes were involved in the regulation of biofilm formation as well as motility.The hydrophobicity and auto-aggregation ability assay results demonstrated an association between the clpB,lmo1438,and lmo0294 genes and bacterial adhesion.However,no significant differences were found regarding this association in the GL002291 and GL002712 genes.This study elucidates some potential regulatory genes associated with biofi lm formation in L.monocytogenes,and laying a theoretical foundation for future research.展开更多
Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors...Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens(HBGAs). Previously, the protruding domain protein(P protein) of human norovirus(genotype Ⅱ.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV(G9 P[8]) in this study. In the system, VP8*could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin(PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.展开更多
Amphichoterpenoids A-C(1-3),unprecedented picoline-derived meroterpenoids possessing a pyrano[3,2-c]pyridinyl-g-pyranone scaffold,were characterized from the ascidian-derived fungus Amphichorda felina SYSU-MS7908.Thei...Amphichoterpenoids A-C(1-3),unprecedented picoline-derived meroterpenoids possessing a pyrano[3,2-c]pyridinyl-g-pyranone scaffold,were characterized from the ascidian-derived fungus Amphichorda felina SYSU-MS7908.Their structures were elucidated by spectroscopic methods,X-ray diffraction and electronic circular dichroism(ECD)calculations.A plausible biosynthetic pathway was proposed.The isolated compounds displayed moderate inhibitory activity against acetylcholinesterase with 50%inhibiting concentration(IC_(50))values of 18.8-53.2 mmol/L.展开更多
Hawanoids A–E(1–5), five highly cyclized diterpenoids were isolated from the deep-sea-derived fungus Paraconiothyrium hawaiiense FS482. Compounds 1 and 2 possessed an unprecedented tetracyclo[6.6.2.0^(2,7).0^(11,15)...Hawanoids A–E(1–5), five highly cyclized diterpenoids were isolated from the deep-sea-derived fungus Paraconiothyrium hawaiiense FS482. Compounds 1 and 2 possessed an unprecedented tetracyclo[6.6.2.0^(2,7).0^(11,15)]cetane carbon skeleton while 3 and 4 possessed an unusual 11,14-macrocyclic ether moiety in phomactin family. Their structures including the stereo-chemistry were determined through spectroscopic analysis, X-ray diffractions and computational calculations. The plausible biosynthetic pathway was proposed based on the predicted biosynthetic gene cluster. All of the isolated compounds exhibited inhibitory activities against PAF-induced platelet aggregation. The molecular docking study was carried out understand the interaction between the PAF receptor and hawanoids with different skeletons.展开更多
Nine new compounds,including five natural rarely-occurring 2,3-dihydro-1H-indene derivatives named diaporindenes E−I(1−5),and four new benzophenone analogues named tenellones J−M(6−9)were isolated from the deep-sea se...Nine new compounds,including five natural rarely-occurring 2,3-dihydro-1H-indene derivatives named diaporindenes E−I(1−5),and four new benzophenone analogues named tenellones J−M(6−9)were isolated from the deep-sea sediment-derived fungus Phomopsis lithocarpus FS508.All the structures for these new compounds were fully characterized on the basis of spectroscopic data,NMR spectra,and ECD calculation and single-crystal X-ray diffraction analysis.The potential anti-tumor activities of compounds 1−9 against four tumor cell lines SF-268,MCF-7,HepG-2,and A549 were evaluated using the SRB method.Compound 7 exhibited cytotoxic activity against the SF-268 cell line with an IC50 value of 11.36μmol·L^(−1).展开更多
基金supported by the National Natural Science Foundation of China (No. 21607031)Science and Technology Planning Project of Guangdong Province, China (Nos. 2014A010107023, 2015B020230002, and 2016A010103020)
文摘Extracellular polymeric substances（EPS） are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions.Extracellular polysaccharides（EP） in EPS are responsible for the formation of microbial aggregates. In this work, we successfully separated and characterized EP from EPS of the bacterium Bacillus megaterium TF10. Extraction of EP from EPS was optimized using Sevag＇s reagent. Chemical characteristics, functional groups, and molecular weight（MW） distribution of EP were compared with the harvested EPS and soluble microbial products（SMP）. We found that the polymers of lower MW and free proteins were successfully removed by Sevag＇s reagent. The higher MW components of EPS were predominantly polysaccharides,while the polymers of lower MW tended to secrete to the supernatant and were described as SMP. A part of the proteins in the EP was polysaccharide-bonded. Our results can be further used in elucidating the complex flocculation mechanisms in which EP play a major role.
基金supported by the National 973 Preliminary Project(No.2014CB460613)the Field Scientific Experimental Station Project of Guangdong academy of science(No.Sytz201512)+1 种基金the Science and Technology Key Program of Guangzhou,China(201607020017)the Science and Technology Planning Project of Guangdong Province(Nos.2014A030304050 and 2015A030302060).
文摘Amomum villosum,Aquilaria sinensis,Morinda officinalis,and Pogostemon cablin are well-known medicinal plants in South China for their particular pharmacological activities,but their endophytic fungi have been rarely reported.Here,the endophytic fungal communities associated with the leaves,stems,and roots of the four medicinal plant species were investigated by high-throughput sequencing technology.From the four medicinal plant species,a total of 169,149 sequences(reads)of endophytic fungi were harvested and clustered into 791 operational taxonomic units(OTUs)assigned to the Kingdom Fungi.These OTUs taxonomically spanned five phyla,27 classes,75 orders,167 families,and 291 genera.At the genus level,Phyllosticta,Candida,Zasmidium,and Cryptococcus were the major genera detected in A.villosum;Nigrospora,Tylopilus,Arthrobotrys,Coniosporium,and Corynespora were the dominant genera isolated in A.sinensis;Ochroconis,Cercospora,Aspergillus,and Cyphellophora were the dominant genera detected in M.officinalis;and Cladophialophora,Meira,Sakaguchia,and Penicillium were the major genera isolated in P.cablin.Among the four medicinal plant species,M.officinalis had the highest endophytic fungal diversity(H′>4.25),however A.sinensis had the lowest(H′<2.37).There were significant differences in endophytic fungal communities among different organs in the same plant species.
基金financially supported by the National Natural Science Foundation of China(Nos.22277147,22177139)the State Key Laboratory of Applied Microbiology South China(No.SKLAM003–2022)。
文摘Two unusual sesquiterpenoids,irpexlactones A(1)and B(2),were isolated from cultures of the basidiomycete Irpex lacteus.Their structures were established by means of spectroscopic methods,the single crystal X-ray diffraction,as well as electronic circular dichroism(ECD)calculations.They possess a novel carbon skeleton with a 5/6/3-fused ring system that may derive from tremulane type sesquiterpenoids with ring-rearrangement.Both compounds show significant inhibitory activities against nitric oxide production with half maximal inhibitory concentration(IC50)values of 2.2 and 1.4μmol/L,respectively.Their anti-inflammatory effects were further evaluated by enzyme-linked immunosorbent assay(ELISA)and Western blot.
基金supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08L213)the National Natural Science Foundation of China(No.42277101).
文摘Hypersaline mariculture wastewater necessitates treatment prior to its discharge into marine environments.Algal-mycelial pellets(AMPs),known for their cost-effectiveness,energy efficiency and sustainability,have not been previously explored for their flocculation and pollutant removal capabilities in hyperhaline conditions.This work employed an orthogonal test design to investigate the effects of nine factors at three levels on the treatment efficiency of mariculture wastewater using Chlorella sp.TNBR1 and Aspergillus niger AMPs.The comprehensive optimal conditions for achieving the highest flocculation efficiency and pollutant removal are determined to be a temperature of 30℃,light intensity of 6000 lux,a 12:0 light-dark cycle,an initial pH of 6,amicroalgal density of 11.25×10^(6)cell/mL,microalgal growth phase at the early logarithmic stage,a fungal spore density of 9.00×10^(5)spore/mL and a fungal pellet phase of 60 h.Under such conditions,the treatment of nonsterile actual mariculture wastewater with Chlorella sp.TNBR1 and Aspergillus niger AMPs results in a 93.35%±7.20%reduction in chemical oxygen demand(COD),92.83%±7.29%reduction in total nitrogen(TN),100%removal of total phosphorus(TP),and a flocculation efficiency of 69.21%±5.36%.These findings confirm that AMPs are a viable solution for effectively treating COD,TN and TP in real hypersaline mariculture wastewater,while also facilitating the flocculation and harvesting of microalgae.
基金financially supported by the National Natural Science Foundation of China (Nos.51478456 and 51178451)
文摘Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.
基金Supported by the research grants from Guangdong Provincial Key Laboratory,No.2020B121201009the Science Foundation of Guangdong Second Provincial General Hospital,No.YQ2019-014GDAS’Project of Science and Technology Development,No.2020GDASYL-20200301002。
文摘BACKGROUND Choledocholithiasis is a severe disorder that affects a significant portion of the world’s population.Treatment using endoscopic sphincterotomy(EST)has become widespread;however,recurrence post-EST is relatively common.The bile microbiome has a profound influence on the recurrence of choledocholithiasis in patients after EST;however,the key pathogens and their functions in the biliary tract remain unclear.AIM To investigate the biliary microbial characteristics of patients with recurrent choledocholithiasis post-EST,using next-generation sequencing.METHODS This cohort study included 43 patients,who presented with choledocholithiasis at the Guangdong Second Provincial General Hospital between May and June 2020.The patients had undergone EST or endoscopic papillary balloon dilation and were followed up for over a year.They were divided into either the stable or recurrent groups.We collected bile samples and extracted microbial DNA for analysis through next-generation sequencing.Resulting sequences were analyzed for core microbiome and statistical differences between the diagnosis groups;they were examined using the Kyoto Encyclopedia of Genes and Genomes pathway hierarchy level using analysis of variance.Correlation between the key genera and metabolic pathways in bile,were analyzed using Pearson’s correlation test.RESULTS The results revealed distinct clustering of biliary microbiota in recurrent choledocholithiasis.Higher relative abundances(RAs)of Fusobacterium and Neisseria(56.61%±14.81%vs 3.47%±1.10%,8.95%±3.42%vs 0.69%±0.32%,respectively)and the absence of Lactobacillus were observed in the bile of patients with recurrent disease,compared to that in stable patients.Construction of a microbiological co-occurrence network revealed a mutual relationship among Fusobacterium,Neisseria,and Leptotrichia,and an antagonistic relationship among Lactobacillales,Fusobacteriales,and Clostridiales.Functional prediction of biliary microbiome revealed that the loss of transcription and metabolic abilities may lead to recurrent choledocholithiasis.Furthermore,the prediction model based on the RA of Lactobacillales in the bile was effective in identifying the risk of recurrent choledocholithiasis(P=0.03).CONCLUSION We demonstrated differences in the bile microbiome of patients with recurrent choledocholithiasis compared to that in patients with stable disease,thereby adding to the current knowledge on its microbiologic etiology.
基金the financial support of National Key Research and Development program, China (2017YFC1601202 and 2017YFC1601200)China Postdoctoral Science Foundation (2021M690854)+2 种基金National Natural Science Foundation of China (31671951 and 31972175)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01S174)Fundamental Research Funds for the Central Universities, China (JZ2020HGQA0151)
文摘Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,and necrotizing enterocolitis in neonates and infants,with neurological sequelae in severe cases.Interest in Cronobacter has increased significantly in recent years due to its high virulence in children.In this review,we summarize the current understanding of the prevalence of Cronobacter species in several important food types.We discuss the response mechanisms enabling persistence in adverse growth con-ditions,as well as its pathogenicity.We emphasize the food safety concerns caused by Cronobacter and subsequent control methods and clinical treatments.
基金National Natural Science Foundation of China,Grant/Award Numbers:51678163,91851202Australian Research Council,Grant/Award Number:FT160100107 and DP180102210。
文摘Synthesis of structurally controlled graphene materials is critical for realizing their practical applications.The electrochemical exfoliation of graphite has emerged as a simple method to produce graphene materials.This review examines research progress in the last 5 years,from 2015 to 2019.Graphene material synthesis methods generally have a trade‐off between increasing production yield and achieving better material property control.The synthesis conditions for synthesizing pristine graphene,graphene oxide(GO),and graphene composites are significantly different.Thus,in this review,we first discuss synthesis methods for graphene materials with high C/O ratios from four aspects:graphite electrodes,equipment engineering,electrolytes,and additional reduction methods.Next,we survey synthesis methods for GO and examine how the pretreatment of the graphite electrodes,electrolytes,and operation parameters,such as applied voltages,electrolyte temperatures,and mechanical forces,affect the quality of GO.Further,we summarize electrochemical exfoliation methods used to dope graphene materials,introduce covalent functional groups,incorporate various nanoparticles,and assembly of graphene architectures.For all synthesis methods,we compare the properties of resulting graphene materials such as C/O ratios,lateral size,layer numbers,and quality characterized by Raman spectroscopy.Lastly,we propose our perspectives on further research.We hope this review stimulates more studies to realize the on‐demand production of graphene materials with desired properties using electrochemical exfoliation methods.
基金financially supported by the Science and Technology Program of Guangzhou, China(No. 201607020018)the Team Project of the Natural Science Foundation of Guangdong Province (No. 2016A030312014)+2 种基金the National Natural Science Foundation of China (No. 31272087)the Guangdong Provincial Project for Science and Technology (Nos. 2015A030302061, 2016A020222022)the Guangdong Provincial Innovative Development of Marine Economy Regional Demonstration Projects (No. GD2012-D01-002)
文摘Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensive spectroscopic analyses, X-ray diffraction and quantum molecular calculation. Their plausible biogenetic pathway featured an intriguing carbonyl-ene cyclization. Lithocarpinol A exhibited moderate inhibitory effect against HepG-2 and A549 tumor cell lines with IC_(50) values of 9.4 μmol/L and10.9 μmol/L,respectively.
基金supported by National Key Research and Development Program for Intergovernmental International Science and Technology Innovation Cooperation(2024YFE0109500)National Natural Science Foundation of China(32072149).
文摘Gastric ulcer is a widespread disease caused by various etiologies.Dendrobium offi cinale flowers exert several health benefits owing to their rich flavonoid content.In this study,protective effects and possible action mechanisms of D.offi cinale flowers’flavonoid enriched extract(DOFF)were assessed against gastric ulcer.The result of sodium nitrite-aluminum nitrate colorimetry showed that 52.34%of the total extractive was flavonoid,and ultra-high performance liquid chromatography time of flight mass spectrometer(UPLC-QTOF/MS)revealed the presence of 28 components in DOFF of which 14 belonged to flavonoids.In addition,in vivo assay revealed DOFF potential in reducing the formation of ethanol-induced gastric mucosal lesions,with drop-in ulcer index from 64.33±8.76 to 32.00±4.47.Similar results were revealed in human gastric mucosal epithelia cells,with cells viability to increase from 27.2%to 61.6%post DOFF administration.To analyzed the protect effect of DOFF,we used Western blotting and immunofluorometric assay to revealed the expression levels of key proteins in cell pathways.The results showed that DOFF(320μg/mL)could increase the level of oxidation marker protein(HO-1),apoptosis regulatory protein(Bcl-2)and autophagy marker(LC3β)by 50.84%,43.85%,and 59.21%compared with ethanol-treated group respectively.Further analyzed of the mitochondrial activity and apoptosis pathway,we found that DOFF appeared to mitigate against ethanolinduced gastric mucosal injury via AMPK/mTOR/ULK1 and PI3K/AKT autophagy signaling pathways.
基金supported by grants from the Natural Science Foundation of China (Grant No.42077040)the open competition program of top ten critical priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province (Grant Nos.2022SDZG09,2023SDZG09)+1 种基金the Natural Science Foundation of Guangdong (Grant No.2021B1515010868)the GDAS Project of Science and Technology Development(2021GDASYL-20210103023)。
文摘Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.
基金supported by the National Natural Science Foundation of China(Nos.31800439 and 32171517)the GDAS’Special Project of Science and Technology Development,China(No.2021GDASYL-20210103023)+1 种基金the Guangdong Special Support Program of China(No.2021JC06N628)the Talent Support Program of Sourthem Marine Science and Engineering Guangdong Laboratory(Guangzhou),China(No.GML20220017)。
文摘Root-associated bacteria play a vital role in the growth and adaptation of host plants to drought stress.These bacteria can be classified as rhizoplane and rhizosphere bacteria based on their distance from the root surface.Tomato plants are often exposed to periodic drought and nitrogen(N)addition throughout their life cycle,but the impacts of these factors on the plant and root-associated bacteria are not well understood.To gain insight into this relationship,we conducted an experiment to monitor the effects of periodic drought and N addition on rhizoplane and rhizosphere bacteria of tomato plants.Drought and N addition had interactive effects on plant and soil properties,which varied with the timing of drought.There were clear divergences in community traits such as alpha diversity,beta diversity,and network topological features between the two types of bacteria.The rhizoplane bacteria showed lower alpha diversity but higher beta diversity and were more sensitive to drought and N addition than the rhizosphere bacteria.Nitrogen addition could downsize the effects of drought on rhizoplane bacterial community compositions.The higher proximity to the root might induce a community to develop more cooperation between different members to cope with plant metabolites,as revealed by the more connected and modularized community network of the rhizoplane bacteria.Drought at the seedling stage had great legacy effects on plant and soil properties.It may enhance selection,cause the dominance of deterministic processes in the assembly of rhizoplane bacteria,and reduce bacterial community network complexity.In conclusion,N addition could interact with drought in affecting tomato plants and their root-associated bacteria,depending on the timing of drought and the fineness of root niches.The higher sensitivity of rhizoplane bacteria to drought and N addition calls for more research due to their higher proximity and importance to plants in future environmental changes.
基金Guangzhou Basic and Applied Basic Research Project(202201010197)State Key Laboratory of Applied Microbiology Southern China(SKLAM011-2021)+1 种基金National Natural Science Foundation of China(32202014),Guangdong Provincial Key Laboratory(2020B121201009)Guangdong Province Academy of Sciences Special Project for Capacity Building of Innovation Driven Development(2020GDASYL-20200401002).
文摘Selenopeptides may be a valuable bioactive compound to promote gut microbiota-targeted therapeutic methods for intestinal disease and hepatopathy.However,limited information is available on the utilization of selenopeptides by gut microbiota,especially Selenium(Se)function.For this purpose,the present study aimed to investigate the protective effect of selenopeptide(RYNA(Se)MNDYT,Se-P2,purity of≥95%)and its original peptide(RYNAMNDYT,P2,purity of≥95%)in vivo by the microbiota-metabolite axis and further analyze the potential contribution of Se biofortification to Se-P2 bioactivity.The results showed that Se-P2 exhibits a higher protective effect on lipopolysaccharide(LPS)-induced inflammation than P2,including pathology of the colon and liver,which suggested that the bioactivity of P2 was promoted by the organic combination of Se.Notably,gut microbiota composition tended to be a healthy structure by Se-P2 pretreatment in LPS-injured mice,which had a positive effect on LPS-induced gut microbiota dysbacteriosis.Additionally,only Se-P2 promoted an increase in the relative abundance of Lactobacillus,Alistipes,and Roseburia and a decrease in the relative abundance of Akkermansia,Erysipelatoclostridium,and Bacteroides in LPS-injured mice.The changes in gut microbiota were obviously correlated with the changes in metabolites and affected the metabolic pathways of valine,leucine,isoleucine,phenylalanine,tyrosine,and tryptophan biosynthesis and phenylalanine metabolism.This may be one of the key reasons for Se-P2 to exert bioactivity through the microbiota-metabolite axis.Furthermore,Se-biofortification in Se-enriched Cordyceps militaris affected the parental proteins of Se-P2 to modulate mitogen-activated protein kinase,GPI anchored protein,and carbohydrate metabolism,translation,folding,sorting and degradation,which may contribute to the bioactivity of Se-P2.Our study provides information on the effect of Se on selenopeptides in vivo,which further promotes the prospective applications of selenopeptides as dietary supplements.
基金supported by the National Natural Science Foundation of China(51308133)Guangdong Provincial National Natural Science Foundation(2014A030308019)+1 种基金Science and Technology Planning Project of Guangdong Province(2015A020215016)the support of Guangdong Institute of Microbiology
文摘Since the azo dyes widely used in textile-dyeing industry are toxic, highly persistent, and ubiquitously distributed in the environment, their treatment efficiencies and fade in ecosystems have received worldwide attention. Due to the microbes play important roles in azo-dye degradation, exogenous nutrient addition is used as a promising biostimulation strategy to improve the treatment efficiencies of azo-dye wastewater. However, little is known about the effects of different kinds of exogenous nutrients on the azo-dye wastewater treatment directly. Here, three kinds of common nutrients, glucose, starch and yeast extract, were added to the sequencing batch reactors （SBR） for the treatment of wastewater containing acid red 73 to compare the biostimulation efficiencies by investigating the dye＇s removal efficiencies and the changes of related water qualities. Our results showed that the reactors added yeast extract had highest removal efficiencies and chemical oxygen demand （COD） as well, followed by glucose and starch. The removal rates of acid red 73 and COD were 90.63% and 8713% in the reactors added yeast extract, respectively, while 86.49% and 78.4% in those with glucose and 85.38% and 75.2% in those with starch. This study provided some useful information for the biostimulation strategy of azo-dye wastewater treatment and preliminarily suggested that yeast extract would be the optimal choice.
基金supported by research grants from the Guangdong Province Basic and Applied Basic Research Fund Project(2022A1515110447)Open Fund Project of the State Key Laboratory of Applied Microbiology in South China(SKLAM006-2022)+1 种基金74th batch of general funding from the China Postdoctoral Science Foundation(2023M740774)Guangdong Provincial People’s Hospital,Postdoctoral Research Launch Fund(BY012022017)。
文摘Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.
基金supported by the National Natural Science Foundation of China(32272295)the Agricultural Independent Innovation Program in Jiangsu Province(CX(23)3043)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0770).
文摘In the food industry,bacterial cells usually adhere to equipment surfaces,forming biofilms that may cause persistent contamination.This study aimed to identify the key genes responsible for the stronger biofilm-forming capability of the Listeria monocytogenes LMB33426 strain compared to that of the L.monocytogenes CICC 21662 strain through comparative genomics.Additionally,the expression of genes and related metabolic pathways of LMB 33426 and CICC 21662 strains were analyzed at the transcriptional level by high-throughput sequencing technology to uncover key differentially expressed genes between planktonic and biofilm cells of those two strains.Subsequently,the key genes found to present differences that were uncovered by those genome-wide and transcriptomic analyses were used to construct gene deletion strains.The crystalline violet assay and motility assay showed that GL002291,GL002712 and Imo1438 genes were involved in the regulation of biofilm formation as well as motility.The hydrophobicity and auto-aggregation ability assay results demonstrated an association between the clpB,lmo1438,and lmo0294 genes and bacterial adhesion.However,no significant differences were found regarding this association in the GL002291 and GL002712 genes.This study elucidates some potential regulatory genes associated with biofi lm formation in L.monocytogenes,and laying a theoretical foundation for future research.
基金the National Key Research and Development Program of China(2017YFF0210200)the National Natural Science Foundation of China(31772078).
文摘Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens(HBGAs). Previously, the protruding domain protein(P protein) of human norovirus(genotype Ⅱ.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV(G9 P[8]) in this study. In the system, VP8*could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin(PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.
基金the National Natural Science Foundation of China(No.41806155)the Guangdong MEPP Fund(No.GDOE(2019)A21)+2 种基金the National Key R&D Program of China(No.2019YFC0312501)the Natural Science Foundation of Guangdong Province(No.2018A030310304)the Key-Area Research and Development Program of Guangdong Province(No.2020B1111030005)for generous support。
文摘Amphichoterpenoids A-C(1-3),unprecedented picoline-derived meroterpenoids possessing a pyrano[3,2-c]pyridinyl-g-pyranone scaffold,were characterized from the ascidian-derived fungus Amphichorda felina SYSU-MS7908.Their structures were elucidated by spectroscopic methods,X-ray diffraction and electronic circular dichroism(ECD)calculations.A plausible biosynthetic pathway was proposed.The isolated compounds displayed moderate inhibitory activity against acetylcholinesterase with 50%inhibiting concentration(IC_(50))values of 18.8-53.2 mmol/L.
基金funded by National Natural Science Foundation of China (Nos. 41906106, 31272087)the Natural Science Foundation of Guangdong Province, China (No. 2021A1515011416)+1 种基金Guangdong Special Support Program (No. 2019TQ05Y375)Guangdong Provincial Special Fund for Marine Economic Development Project (No. GDNRC [2021]054)。
文摘Hawanoids A–E(1–5), five highly cyclized diterpenoids were isolated from the deep-sea-derived fungus Paraconiothyrium hawaiiense FS482. Compounds 1 and 2 possessed an unprecedented tetracyclo[6.6.2.0^(2,7).0^(11,15)]cetane carbon skeleton while 3 and 4 possessed an unusual 11,14-macrocyclic ether moiety in phomactin family. Their structures including the stereo-chemistry were determined through spectroscopic analysis, X-ray diffractions and computational calculations. The plausible biosynthetic pathway was proposed based on the predicted biosynthetic gene cluster. All of the isolated compounds exhibited inhibitory activities against PAF-induced platelet aggregation. The molecular docking study was carried out understand the interaction between the PAF receptor and hawanoids with different skeletons.
基金This work was supported by Guangdong Provincial Special Fund for Marine Economic Development Project(No.GDNRC[2020]042)the National Natural Science Foundation of China(No.41906106)+2 种基金Guangdong Special Support Program(No.2019TQ05Y375)the Team Project of the Natural Science Foundation of Guangdong Province(No.2016A030312014)the GDAS'Project of Science and Technology Development(No.2019GDA-SYL-0103007).
文摘Nine new compounds,including five natural rarely-occurring 2,3-dihydro-1H-indene derivatives named diaporindenes E−I(1−5),and four new benzophenone analogues named tenellones J−M(6−9)were isolated from the deep-sea sediment-derived fungus Phomopsis lithocarpus FS508.All the structures for these new compounds were fully characterized on the basis of spectroscopic data,NMR spectra,and ECD calculation and single-crystal X-ray diffraction analysis.The potential anti-tumor activities of compounds 1−9 against four tumor cell lines SF-268,MCF-7,HepG-2,and A549 were evaluated using the SRB method.Compound 7 exhibited cytotoxic activity against the SF-268 cell line with an IC50 value of 11.36μmol·L^(−1).
