Inoculated fermentation enables rapid fermentation of aquatic products.No studies have been conducted on the lipid profiles of inoculated fermented golden pompano(Trachinotus ovatus).In this study,a lipase-producing B...Inoculated fermentation enables rapid fermentation of aquatic products.No studies have been conducted on the lipid profiles of inoculated fermented golden pompano(Trachinotus ovatus).In this study,a lipase-producing Bacillus subtilis with salt tolerance was screened from traditionally fermented golden pompano(TF)and used as a starter culture.Whole-genome sequencing analysis revealed it carries 4 clustered regularly interspaced short vpalindromic repeats structures and 2 genes encoding triacylglycerol lipase.Untargeted lipidomics identified lipid molecules(833)in 6 major classes from B.subtilis SCSMX-2 fermented golden pompano(IF).A total of 28 lipid molecules were upregulated in IF,including phosphatidylcholines(PCs),triacylglycerols(TAGs),and lysophosphatidylcholine.B.subtilis supplementation enhanced the production of polyenyl PCs and mediumand long-chain TAGs.The IF rich in linoleic,docosahexaenoic acids(DHA),and eicosapentaenoic acid were primarily distributed in the sn-2 position of DHA,PC and phosphatidylethanolamine.This research revealed the lipid profiles of IF,providing theoretical basis for the application of B.subtilis in the fermented fish industry.展开更多
Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between pr...Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.展开更多
Popular fermented golden pomfret(Trachinotus ovatus)is prepared via spontaneous fermentation;however,the mechanisms underlying the regulation of its flavor development remain unclear.This study shows the roles of the ...Popular fermented golden pomfret(Trachinotus ovatus)is prepared via spontaneous fermentation;however,the mechanisms underlying the regulation of its flavor development remain unclear.This study shows the roles of the complex microbiota and the dynamic changes in microbial community and flavor compounds during fish fermentation.Single-molecule real-time sequencing and molecular networking analysis revealed the correlations among different microbial genera and the relationships between microbial taxa and volatile compounds.Mechanisms underlying flavor development were also elucidated via KEGG based functional annotations.Clostridium,Shewanella,and Staphylococcus were the dominant microbial genera.Forty-nine volatile compounds were detected in the fermented fish samples,with thirteen identified as characteristic volatile compounds(ROAV>1).Volatile profiles resulted from the interactions among the microorganisms and derived enzymes,with the main metabolic pathways being amino acid biosynthesis/metabolism,carbon metabolism,and glycolysis/gluconeogenesis.This study demonstrated the approaches for distinguishing key microbiota associated with volatile compounds and monitoring the industrial production of high-quality fermented fish products.展开更多
Quality deterioration induced by microbial community in Litopenaeus vannamei during superchilling storage were demonstrated in this study.In this study,6 microorganisms were identified as the biomarkers by 16S rDNA se...Quality deterioration induced by microbial community in Litopenaeus vannamei during superchilling storage were demonstrated in this study.In this study,6 microorganisms were identified as the biomarkers by 16S rDNA sequencing and 71 differential metabolites were identified by untargeted metabolomics.The correlation analysis between microorganisms and differential metabolites revealed that Oceanicaulis,Aliihoeflea,Prauserella,Chelativorans and Pseudoalteromonas had the potential to be the important microorganisms of deterioration of superchilled shrimp.Moreover,the spearman correlation analysis revealed that lightness value had highly significant correlation with Shewanella(P<0.01),and thiobarbituric acid content,total viable count value,total sulfhydryl content,trichloroacetic acid-soluble peptide and Ca2+-ATPase activity showed significantly correlation with Oceanicaulis,Prauserella,Chelativorans,Aliihoefl ea and Pseudoalteromonas(P<0.05).This study offers a better understanding for mechanisms behind quality degradation induced by microorganisms,which may help the quality maintaining of Pacific white shrimp during superchilling storage.展开更多
Fermented foods are a potential source to produce novel dipeptidyl peptidase-IV inhibitory peptides(D4IPs).In this study,the fermented mandarin fish(Chouguiyu)was used to screen D4IPs and their formation mechanism was...Fermented foods are a potential source to produce novel dipeptidyl peptidase-IV inhibitory peptides(D4IPs).In this study,the fermented mandarin fish(Chouguiyu)was used to screen D4IPs and their formation mechanism was studied by metagenomics and peptidomics.A total of 400 D4IPs with DPP-IV inhibition structure and high hydrophobicity were identified.The correlation network map showed that Lactococcus,Bacillus,Lysobacter,Pelagivirga,Kocuria,Escherichia,Streptococcus,and Peptostreptococcus were significantly correlated with the most D4IPs.Four stable D4IPs,including KAGARALTDAETAT,GEKVDFDDIQK,VVDADEMYLKGK,and GQKDSYVGDEAQ were respectively from the precursor proteins parvalbumin,troponin,myosin,and actin,and were mainly formed by the hydrolysis of subtilisin(EC 3.4.21.62),aspartic proteinase(EC 3.4.23.1),thermolysin(EC 3.4.24.27),oligopeptidase B(EC 3.4.21.83),and proteinase P1(EC 3.4.21.96)from Bacillus,Kocuria,Lysobacter,Lactococcus,and Peptostreptococcus.The inhibition mainly resulted from the hydrogen bond and salt bridge between D4IPs and DPP-IV enzyme.This study provides important information on the proteases and related microbial strains to directionally prepare D4IPs in Chouguiyu.展开更多
Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting prese...Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting presents a promising avenue to offset the energy demands of buildings.The disparity in diffusion rate between cations and anions within cement pore solution due to variations in interactions with pore walls,endows cement with inherent ionic thermoelectric properties.However,the isolation of pores by the dense cement matrix hinders the rapid transportation of ions with superior diffusion rates,impeding the enhancement of mobility difference between ions and limiting the enhancement of Seebeck coefficient.Inspired by the stem structure of plants,we present a cement-polyvinyl alcohol(PVA)composite(CPC)featuring aligned cement and PVA hydrogel layers.While PVA hydrogel layers provide ion diffusion highways for OH-ions,cement-PVA interfaces establish strong coordination bonds with Ca^(2+)ions and weaker interactions with OH-ions,enabling selective immobilization,which amplifies the diffusion rate disparity between Ca^(2+)and OH^(-).The CPC's multilayer structure yields abundant interfaces,providing ample interaction sites that maximize the contribution of cement ions to thermoelectric performance.The as-prepared composite achieves an impressive Seebeck coefficient of-40.5 mV/K and a figure of merit(ZT)of 6.6×10^(-2).Due to the engineered multilayer structure,the CPC also demonstrates superior mechanical strength and intrinsic energy storage potential,which has been assembled into a selfpowered architecture.The biomimetic structure and interfacial selective immobilization mechanism may pave the way for the design and fabrication of high-performance ionic thermoelectric materials.展开更多
Volatile organic compounds are important indicators of the characteristic flavor of traditional fermented fish products. In the present study, gas chromatography-ion mobility mass spectrometry (GC-IMS) and gas chromat...Volatile organic compounds are important indicators of the characteristic flavor of traditional fermented fish products. In the present study, gas chromatography-ion mobility mass spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) were used to identify and quantify the volatile organic compounds (VOCs) in fermented sea bass. Thirty-six and 104 VOCs were identified by GC-IMS and GC-MS, respectively. Aldehydes were the principal contributors to the formation of the overall flavor of fermented sea bass. The characteristic VOCs in fermented sea bass were identified based on loading plots. GC-IMS and GC-MS, along with variable influence on projection (VIP), identified six and four VOCs as biomarkers, respectively, in fermented sea bass. This investigation demonstrated that GC-IMS could rapidly detect VOCs in a simple manner in fermented sea bass. The results of the present study also provide a theoretical basis for determining flavor formation in fermented sea bass.展开更多
This study aimed to isolate and identify the novel potential Xanthine oxidase(XOD)inhibitory peptides derived from Trachinotus ovatus hydrolysate(TOH)(hydrolysis by neutral protease),and investigate their structure-fu...This study aimed to isolate and identify the novel potential Xanthine oxidase(XOD)inhibitory peptides derived from Trachinotus ovatus hydrolysate(TOH)(hydrolysis by neutral protease),and investigate their structure-function relationship.Initially,TOH was separated to four fractions(F1–F4)by gel filtration chromatography and F4 was chosen with higher XOD inhibitory rate(85.16%±0.566,25 mg/mL)and lower molecular weight(95.73%,<1000 Da).F4 was further characterized by reversed-phase high performance liquid chromatography(RP-HPLC)coupled with Nano-HPLC-MS/MS and four peptides(FPAW,LLPW,WLLP and FHLP)were identified with IC50 value of 3.81±0.18 mM,4.17±0.12 mM,43.06±0.73 mM,and over 50.00 mM respectively.It can be concluded that Trp-containing peptides especially located in C-terminal could inhibit XOD effectively.Moreover,the XOD-inhibiting actions of these peptides involvedπ-πstacking(Phe914 and Phe1009 in XOD),hydrogen bonding via molecular docking.Lineweaver-Burk equation showed the inhibition type of FPAW was a mixed inhibition.Circular dichroism(CD)spectra indicated FPAW could combine and change the secondary structure of XOD.Therefore,two peptides of FPAW and LLPW might have potential to be used to alleviate hyperuricemia in the future.展开更多
We investigated the Fe^(2+)chelating properties and the mechanism of improving Fe^(2+)bioavailability of the Fe^(2+)chelating peptide(GLPGPSGEEGKR,peptide-G-R).Fe^(2+)was chelated with the carboxyl oxygen atom of the ...We investigated the Fe^(2+)chelating properties and the mechanism of improving Fe^(2+)bioavailability of the Fe^(2+)chelating peptide(GLPGPSGEEGKR,peptide-G-R).Fe^(2+)was chelated with the carboxyl oxygen atom of the Glu-Glu residue in the form of monodentate and bidentate chelating mode.After chelation,peptide-G-R was folded and aggregated to form spherical particles with increasing particle size.Peptide-G-R could increase the Fe^(2+)transport/retention/uptake rate and the relative expression levels of divalent metal transporter 1(DMT1)in the Caco-2 cells monolayer model.Peptide-G-R could reverse the inhibition of phytic acid on the Fe^(2+)utilization in the Caco-2 cells monolayer model.Molecular dynamics simulation showed that peptide-G-R interacted with DMT1 in the form of intermolecular hydrogen bonds.The transport mechanism of the peptide-G-R-Fe^(2+)complex included endocytosis(main pathway),paracellular pathway(auxiliary way),and DMT1(potential pathway).Thus,peptide-G-R derived from tilapia skin collagen could be used as a dietary iron supplement.展开更多
Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAE...Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAEW)were used to produce ready-to-eat jellyfish.The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis.Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment.The increase of total plate count(TPC)and pH value during storage was significantly inhibited by SAEW,while the other properties did not changed significantly.Staphylococcus,especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW.The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group,while the correlated microbial genera mainly changed to Acinetobacter,Cutibacterium,and Pseudomonas after SAEW treatment,resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage.The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment.This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.展开更多
The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,re...The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,resulting in the project funding not being listed.展开更多
The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,re...The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,resulting in the project funding not being listed.展开更多
The objective of this study was to examine the impact of glycosylation reaction on the protein structure of tilapia and its digestibility for the elderly.It was established that an increase in glycosylation time resul...The objective of this study was to examine the impact of glycosylation reaction on the protein structure of tilapia and its digestibility for the elderly.It was established that an increase in glycosylation time resulted in a gradual transformation of the solution’s colour from yellow to brown,accompanied by the generation of precipitation.Concurrently,the average particle size of the protein increased significantly,from 7.53 nm to 43.82 nm.This change was concomitant with alterations in protein structure.Gastric hydrolysis of glycated protein T0-12 decreased from 22.25% to 5.23%,which,in addition to the lack of gastric acid in the elderly,may be due to protein aggregation,induced by glycation.However,the process of intestinal digestion was less impacted,with hydrolysis of glycated protein T0-12 ranging from 54.65%to 60.63%,which may be due to multiple proteases in trypsin counteracting glycation.In conclusion,glycated tilapia proteins may limit gastric digestion,but have little effect on intestinal digestibility.展开更多
The aims of this study were to investigate the effect of precise phosphorylation of Ser in GL-Hyp-GPSGEEGKR on its Fe^(2+)chelating capacity,and the effects and mechanisms of folic acid coupling to GL-Hyp-GPS_((PO4))G...The aims of this study were to investigate the effect of precise phosphorylation of Ser in GL-Hyp-GPSGEEGKR on its Fe^(2+)chelating capacity,and the effects and mechanisms of folic acid coupling to GL-Hyp-GPS_((PO4))GEEGKR on its resistance against degradation by gastrointestinal enzymes.The results demonstrated that GL-Hyp-GPS_((PO4))GEEGKR exhibited significantly enhanced Fe^(2+)chelating capability compared to GL-Hyp-GPSGEEGKR.This was attributed to the phosphorylation of Ser introducing more Fe^(2+)chelating sites.Furthermore,the results of UV-Vis,FTIR,and ^(1)H NMR showed that folic acid has successfully coupled with GL-Hyp-GPS_((PO4))GEEGKR to generate folic acid-GL-Hyp-GPS_((PO4))GEEGKR.Folic acid-GL-Hyp-GPS_((PO4))GEEGKR demonstrated superior resistance against degradation by gastrointestinal enzymes.This may be attributed to the coupling of folic acid altering the original zeta potential of the peptide and the steric hindrance effect of folic acid hindering the interaction between enzymes and peptide.These findings can provide valuable insights for the production of high Fe^(2+)chelating peptides that resist gastrointestinal enzyme degradation.展开更多
In fermented fish products,microorganisms catalyze protein degradation by secreting proteases,thereby altering the nutritional values of foods.In this study,we isolated a high proteinase-producing strain from fermente...In fermented fish products,microorganisms catalyze protein degradation by secreting proteases,thereby altering the nutritional values of foods.In this study,we isolated a high proteinase-producing strain from fermented golden pompano(Trachinotus ovatus),and from the 16S rRNA,we identified the strain as Bacillus tropicus,which we named Bacillus tropicus MX-8.This strain could form a distinct proteolytic circle around the colony when plated on agar containing 3%skimmed milk powder and could grow under 0-5%salinity.Its protease significantly degraded fish proteins.Genome sequencing analysis revealed that the genome of B.tropicus MX-8 comprised one circular chromosome and three circular plasmids.A total of 27 genes encoding proteases,including a neutral protease and three serine proteases,were identified in the non-redundant protein database.Homology modeling showed that serine protease 2 had the best model quality and the highest sequence match.Molecular docking experiments revealed the presence of several amino acid active sites on serine protease 2.These active sites mainly rely on hydrogen bonding to interact with actin heavy chains and myosin to form complexes,which can promote further protein degradation.This study demonstrated that B.tropicus MX-8 has the potential to ferment fish,providing a theoretical basis for the production of rapidly fermented fish products.展开更多
This study explores the potential of silver carp by-product hydrolysate(SCBH)as a sustainable and cost-effective alternative to mucin for cultivating Akkermansia muciniphila(Akk),a beneficial probiotic known to help p...This study explores the potential of silver carp by-product hydrolysate(SCBH)as a sustainable and cost-effective alternative to mucin for cultivating Akkermansia muciniphila(Akk),a beneficial probiotic known to help prevent metabolic diseases like obesity,type II diabetes,and inflammatory bowel diseases.Traditionally,Akk relies on mucin in BHI medium,which is expensive and poses potential risks,including the transmission of swine influ-enza and restrictions due to religious considerations.We evaluated SCBH’s effects on Akk’s growth,morphology,and metabolic activity,focusing on short-chain fatty acids(SCFAs)production and the underlying mechanisms through which SCBH influences its growth and metabolism.Metabolomic analysis revealed that SCBH signifi-cantly(p<0.05)enhanced propionic,butyric,and isovaleric acid production by 19.05%,332.33%,and 35.88%,respectively.Additionally,SCBH promoted the synthesis of unsaturated fatty acid,supported amino acid metabolism,and increased taurine production while inhibiting ferroptosis,which may collectively enhancing Akk’s probiotic potential.SCBH also preserved Akk’s key morphological traits.These findings demonstrate SCBH’s efficacy as a mucin substitute,offering a novel and sustainable strategy for valorizing silver carp by-products and advancing Akk cultivation.This research provides mechanistic insights into SCBH’s role in opti-mizing Akk’s metabolic and functional properties.展开更多
基金supported by the National Natural Science Foundation of China(32372367)the earmarked fund for CARS(CARS-47)+1 种基金Natural Science Foundation of Hainan Provine(323CXTD391)the Special Scientific Research Funds for Central Non-profit Institutes and the Chinese Academy of Fishery Sciences(2020TD69)。
文摘Inoculated fermentation enables rapid fermentation of aquatic products.No studies have been conducted on the lipid profiles of inoculated fermented golden pompano(Trachinotus ovatus).In this study,a lipase-producing Bacillus subtilis with salt tolerance was screened from traditionally fermented golden pompano(TF)and used as a starter culture.Whole-genome sequencing analysis revealed it carries 4 clustered regularly interspaced short vpalindromic repeats structures and 2 genes encoding triacylglycerol lipase.Untargeted lipidomics identified lipid molecules(833)in 6 major classes from B.subtilis SCSMX-2 fermented golden pompano(IF).A total of 28 lipid molecules were upregulated in IF,including phosphatidylcholines(PCs),triacylglycerols(TAGs),and lysophosphatidylcholine.B.subtilis supplementation enhanced the production of polyenyl PCs and mediumand long-chain TAGs.The IF rich in linoleic,docosahexaenoic acids(DHA),and eicosapentaenoic acid were primarily distributed in the sn-2 position of DHA,PC and phosphatidylethanolamine.This research revealed the lipid profiles of IF,providing theoretical basis for the application of B.subtilis in the fermented fish industry.
基金supported by Central Public-Interest Scientific Institution Basal Research Fund,CAFS(2023TD74,2023TD78)the Earmarked Fund for CARS-47(CARS-47)+2 种基金Guangdong Provincial Science and Technology Plan Project(2023B0202010015)Central Public-Interest Scientific Institution Basal Research Fund,CAFS(Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-013))Special Funds for Promoting Economic Development in Guangdong Province(For Modern Fishery)(YueNong 2019B14).
文摘Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.
基金supported by the National Natural Science Foundation of China(32001733)the Earmarked fund for CARS(CARS-47)+3 种基金Guangxi Natural Science Foundation Program(2021GXNSFAA196023)Guangdong Basic and Applied Basic Research Foundation(2021A1515010833)Young Talent Support Project of Guangzhou Association for Science and Technology(QT20220101142)the Special Scientific Research Funds for Central Non-profit Institutes,Chinese Academy of Fishery Sciences(2020TD69)。
文摘Popular fermented golden pomfret(Trachinotus ovatus)is prepared via spontaneous fermentation;however,the mechanisms underlying the regulation of its flavor development remain unclear.This study shows the roles of the complex microbiota and the dynamic changes in microbial community and flavor compounds during fish fermentation.Single-molecule real-time sequencing and molecular networking analysis revealed the correlations among different microbial genera and the relationships between microbial taxa and volatile compounds.Mechanisms underlying flavor development were also elucidated via KEGG based functional annotations.Clostridium,Shewanella,and Staphylococcus were the dominant microbial genera.Forty-nine volatile compounds were detected in the fermented fish samples,with thirteen identified as characteristic volatile compounds(ROAV>1).Volatile profiles resulted from the interactions among the microorganisms and derived enzymes,with the main metabolic pathways being amino acid biosynthesis/metabolism,carbon metabolism,and glycolysis/gluconeogenesis.This study demonstrated the approaches for distinguishing key microbiota associated with volatile compounds and monitoring the industrial production of high-quality fermented fish products.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2020A1515110360)Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(320LH037)+3 种基金Hainan Provincial Natural Sciences Foundation of China(322QN434)Guangzhou Basic and Applied Basic Research Foundation(202102021062)Research and Development Projects in Key Areas of Guangdong Province,China(2021B0202060002)Postgraduate Education Innovation Project of Guangdong Ocean University(202242).
文摘Quality deterioration induced by microbial community in Litopenaeus vannamei during superchilling storage were demonstrated in this study.In this study,6 microorganisms were identified as the biomarkers by 16S rDNA sequencing and 71 differential metabolites were identified by untargeted metabolomics.The correlation analysis between microorganisms and differential metabolites revealed that Oceanicaulis,Aliihoeflea,Prauserella,Chelativorans and Pseudoalteromonas had the potential to be the important microorganisms of deterioration of superchilled shrimp.Moreover,the spearman correlation analysis revealed that lightness value had highly significant correlation with Shewanella(P<0.01),and thiobarbituric acid content,total viable count value,total sulfhydryl content,trichloroacetic acid-soluble peptide and Ca2+-ATPase activity showed significantly correlation with Oceanicaulis,Prauserella,Chelativorans,Aliihoefl ea and Pseudoalteromonas(P<0.05).This study offers a better understanding for mechanisms behind quality degradation induced by microorganisms,which may help the quality maintaining of Pacific white shrimp during superchilling storage.
基金financially supported by the National Key R&D Program of China(2019YFD0901903)the China Agriculture Research System of MOF and MARA(CARS-46,CARS-47)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515010872)the Young S&T Talent Training Program of Guangdong Provincial Association for S&T,China(SKXRC202210)the Pearl River S&T Nova Program of Guangzhou(201906010081)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD69).
文摘Fermented foods are a potential source to produce novel dipeptidyl peptidase-IV inhibitory peptides(D4IPs).In this study,the fermented mandarin fish(Chouguiyu)was used to screen D4IPs and their formation mechanism was studied by metagenomics and peptidomics.A total of 400 D4IPs with DPP-IV inhibition structure and high hydrophobicity were identified.The correlation network map showed that Lactococcus,Bacillus,Lysobacter,Pelagivirga,Kocuria,Escherichia,Streptococcus,and Peptostreptococcus were significantly correlated with the most D4IPs.Four stable D4IPs,including KAGARALTDAETAT,GEKVDFDDIQK,VVDADEMYLKGK,and GQKDSYVGDEAQ were respectively from the precursor proteins parvalbumin,troponin,myosin,and actin,and were mainly formed by the hydrolysis of subtilisin(EC 3.4.21.62),aspartic proteinase(EC 3.4.23.1),thermolysin(EC 3.4.24.27),oligopeptidase B(EC 3.4.21.83),and proteinase P1(EC 3.4.21.96)from Bacillus,Kocuria,Lysobacter,Lactococcus,and Peptostreptococcus.The inhibition mainly resulted from the hydrogen bond and salt bridge between D4IPs and DPP-IV enzyme.This study provides important information on the proteases and related microbial strains to directionally prepare D4IPs in Chouguiyu.
基金supported by the National Natural Science Foundation of China(52250010 and 52379120)the Natural Science Foundation of Jiangsu Province(BK20230086)。
文摘Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting presents a promising avenue to offset the energy demands of buildings.The disparity in diffusion rate between cations and anions within cement pore solution due to variations in interactions with pore walls,endows cement with inherent ionic thermoelectric properties.However,the isolation of pores by the dense cement matrix hinders the rapid transportation of ions with superior diffusion rates,impeding the enhancement of mobility difference between ions and limiting the enhancement of Seebeck coefficient.Inspired by the stem structure of plants,we present a cement-polyvinyl alcohol(PVA)composite(CPC)featuring aligned cement and PVA hydrogel layers.While PVA hydrogel layers provide ion diffusion highways for OH-ions,cement-PVA interfaces establish strong coordination bonds with Ca^(2+)ions and weaker interactions with OH-ions,enabling selective immobilization,which amplifies the diffusion rate disparity between Ca^(2+)and OH^(-).The CPC's multilayer structure yields abundant interfaces,providing ample interaction sites that maximize the contribution of cement ions to thermoelectric performance.The as-prepared composite achieves an impressive Seebeck coefficient of-40.5 mV/K and a figure of merit(ZT)of 6.6×10^(-2).Due to the engineered multilayer structure,the CPC also demonstrates superior mechanical strength and intrinsic energy storage potential,which has been assembled into a selfpowered architecture.The biomimetic structure and interfacial selective immobilization mechanism may pave the way for the design and fabrication of high-performance ionic thermoelectric materials.
基金supported by the National Natural Science Foundation of China[32001733]the Earmarked fund for CARS[CARS-46 and CARS-47]+2 种基金the Guangdong Basic and Applied Basic Research Foundation[2021A1515010833]Young Talent Support Project of Guangzhou Association for Science and Technology[QT20220101142]the Special Scientific Research Funds for Central Non-profit Institutes and Chinese Academy of Fishery Sciences[2020TD69].
文摘Volatile organic compounds are important indicators of the characteristic flavor of traditional fermented fish products. In the present study, gas chromatography-ion mobility mass spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) were used to identify and quantify the volatile organic compounds (VOCs) in fermented sea bass. Thirty-six and 104 VOCs were identified by GC-IMS and GC-MS, respectively. Aldehydes were the principal contributors to the formation of the overall flavor of fermented sea bass. The characteristic VOCs in fermented sea bass were identified based on loading plots. GC-IMS and GC-MS, along with variable influence on projection (VIP), identified six and four VOCs as biomarkers, respectively, in fermented sea bass. This investigation demonstrated that GC-IMS could rapidly detect VOCs in a simple manner in fermented sea bass. The results of the present study also provide a theoretical basis for determining flavor formation in fermented sea bass.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B1111030004)the Guangdong Basic and Applied Basic Research Foundation(2019A1515011588)+4 种基金the Pearl River S&T Nova Program of Guangzhou(201906010081)the China Agriculture Research System of MOF and MARA(CARS-47)the Special Scientific Research Funds for Central Non-profit Institutes,Chinese Academy of Fishery Sciences(2020TD69)the Central Public-interest Scientific Institution Basal Research Funds,South China Sea Fisheries Research Institute,CAFS(2021SD06)Qingdao Science and technology benefit people special project(20-3-4-31-nsh).
文摘This study aimed to isolate and identify the novel potential Xanthine oxidase(XOD)inhibitory peptides derived from Trachinotus ovatus hydrolysate(TOH)(hydrolysis by neutral protease),and investigate their structure-function relationship.Initially,TOH was separated to four fractions(F1–F4)by gel filtration chromatography and F4 was chosen with higher XOD inhibitory rate(85.16%±0.566,25 mg/mL)and lower molecular weight(95.73%,<1000 Da).F4 was further characterized by reversed-phase high performance liquid chromatography(RP-HPLC)coupled with Nano-HPLC-MS/MS and four peptides(FPAW,LLPW,WLLP and FHLP)were identified with IC50 value of 3.81±0.18 mM,4.17±0.12 mM,43.06±0.73 mM,and over 50.00 mM respectively.It can be concluded that Trp-containing peptides especially located in C-terminal could inhibit XOD effectively.Moreover,the XOD-inhibiting actions of these peptides involvedπ-πstacking(Phe914 and Phe1009 in XOD),hydrogen bonding via molecular docking.Lineweaver-Burk equation showed the inhibition type of FPAW was a mixed inhibition.Circular dichroism(CD)spectra indicated FPAW could combine and change the secondary structure of XOD.Therefore,two peptides of FPAW and LLPW might have potential to be used to alleviate hyperuricemia in the future.
基金supported by the National Key R&D Program of China(2018YFD0901102)the Key-Area Research and Development Program of Guangdong Province(2020B020226005)+4 种基金the China Agriculture Research System of MOF and MARA(CARS-46)he National Natural Science Foundation of China(31301454)the Special Scientific Research Funds for Central Non-profit Institutes,Chinese Academy of Fishery Sciences(2020TD69)the Central Public-interest Scientific Institution Basal Research Funds,South China Sea Fisheries Research Institute,CAFS(2021SD06)the Pearl River S&T Nova Program of Guangzhou(201906010081).
文摘We investigated the Fe^(2+)chelating properties and the mechanism of improving Fe^(2+)bioavailability of the Fe^(2+)chelating peptide(GLPGPSGEEGKR,peptide-G-R).Fe^(2+)was chelated with the carboxyl oxygen atom of the Glu-Glu residue in the form of monodentate and bidentate chelating mode.After chelation,peptide-G-R was folded and aggregated to form spherical particles with increasing particle size.Peptide-G-R could increase the Fe^(2+)transport/retention/uptake rate and the relative expression levels of divalent metal transporter 1(DMT1)in the Caco-2 cells monolayer model.Peptide-G-R could reverse the inhibition of phytic acid on the Fe^(2+)utilization in the Caco-2 cells monolayer model.Molecular dynamics simulation showed that peptide-G-R interacted with DMT1 in the form of intermolecular hydrogen bonds.The transport mechanism of the peptide-G-R-Fe^(2+)complex included endocytosis(main pathway),paracellular pathway(auxiliary way),and DMT1(potential pathway).Thus,peptide-G-R derived from tilapia skin collagen could be used as a dietary iron supplement.
基金financially supported by the Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams(2023KJ151)the Youth Talent Support Programme of Guangdong Provincial Association for Science and Technology(SKXRC202210)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD69)the Key Laboratory of Aquatic Product Processing,Ministry of Agriculture and Rural Affairs,China(NYJG201309).
文摘Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAEW)were used to produce ready-to-eat jellyfish.The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis.Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment.The increase of total plate count(TPC)and pH value during storage was significantly inhibited by SAEW,while the other properties did not changed significantly.Staphylococcus,especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW.The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group,while the correlated microbial genera mainly changed to Acinetobacter,Cutibacterium,and Pseudomonas after SAEW treatment,resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage.The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment.This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.
文摘The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,resulting in the project funding not being listed.
文摘The authors regret that due to our negligence and lack of experience,only the project name and number were filled in the online submission interface and did not list it separately in the acknowledgements at the end,resulting in the project funding not being listed.
文摘The objective of this study was to examine the impact of glycosylation reaction on the protein structure of tilapia and its digestibility for the elderly.It was established that an increase in glycosylation time resulted in a gradual transformation of the solution’s colour from yellow to brown,accompanied by the generation of precipitation.Concurrently,the average particle size of the protein increased significantly,from 7.53 nm to 43.82 nm.This change was concomitant with alterations in protein structure.Gastric hydrolysis of glycated protein T0-12 decreased from 22.25% to 5.23%,which,in addition to the lack of gastric acid in the elderly,may be due to protein aggregation,induced by glycation.However,the process of intestinal digestion was less impacted,with hydrolysis of glycated protein T0-12 ranging from 54.65%to 60.63%,which may be due to multiple proteases in trypsin counteracting glycation.In conclusion,glycated tilapia proteins may limit gastric digestion,but have little effect on intestinal digestibility.
基金the financial support from the National Key R&D Program of China(2022YFD2100905)the earmarked fund for CARS(CARS-46)+2 种基金the National Natural Science Foundation of China(32372250)the Hainan Provincial Natural Science Foundation(323MS12)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD74).
文摘The aims of this study were to investigate the effect of precise phosphorylation of Ser in GL-Hyp-GPSGEEGKR on its Fe^(2+)chelating capacity,and the effects and mechanisms of folic acid coupling to GL-Hyp-GPS_((PO4))GEEGKR on its resistance against degradation by gastrointestinal enzymes.The results demonstrated that GL-Hyp-GPS_((PO4))GEEGKR exhibited significantly enhanced Fe^(2+)chelating capability compared to GL-Hyp-GPSGEEGKR.This was attributed to the phosphorylation of Ser introducing more Fe^(2+)chelating sites.Furthermore,the results of UV-Vis,FTIR,and ^(1)H NMR showed that folic acid has successfully coupled with GL-Hyp-GPS_((PO4))GEEGKR to generate folic acid-GL-Hyp-GPS_((PO4))GEEGKR.Folic acid-GL-Hyp-GPS_((PO4))GEEGKR demonstrated superior resistance against degradation by gastrointestinal enzymes.This may be attributed to the coupling of folic acid altering the original zeta potential of the peptide and the steric hindrance effect of folic acid hindering the interaction between enzymes and peptide.These findings can provide valuable insights for the production of high Fe^(2+)chelating peptides that resist gastrointestinal enzyme degradation.
基金supported by the National Natural Science Foundation of China[grant number 32372367]The earmarked fund for CARS[grant number CARS-47]+2 种基金Natural Science Foundation of Hainan Province[grant number 323CXTD391]Young Talent Support Project of Guangzhou Association for Science and Technology[grant number QT20220101142]the Special Scientific Research Funds for Central Non-Profit Institutes and the Chinese Academy of Fishery Sciences[grant number 2020TD69].
文摘In fermented fish products,microorganisms catalyze protein degradation by secreting proteases,thereby altering the nutritional values of foods.In this study,we isolated a high proteinase-producing strain from fermented golden pompano(Trachinotus ovatus),and from the 16S rRNA,we identified the strain as Bacillus tropicus,which we named Bacillus tropicus MX-8.This strain could form a distinct proteolytic circle around the colony when plated on agar containing 3%skimmed milk powder and could grow under 0-5%salinity.Its protease significantly degraded fish proteins.Genome sequencing analysis revealed that the genome of B.tropicus MX-8 comprised one circular chromosome and three circular plasmids.A total of 27 genes encoding proteases,including a neutral protease and three serine proteases,were identified in the non-redundant protein database.Homology modeling showed that serine protease 2 had the best model quality and the highest sequence match.Molecular docking experiments revealed the presence of several amino acid active sites on serine protease 2.These active sites mainly rely on hydrogen bonding to interact with actin heavy chains and myosin to form complexes,which can promote further protein degradation.This study demonstrated that B.tropicus MX-8 has the potential to ferment fish,providing a theoretical basis for the production of rapidly fermented fish products.
基金supported by the National Key R&D Program of China(2022YFD2100905)the Fund of Key Laboratory of Aquatic Product Processing,Ministry of Agriculture and Rural Affairs,China(NYJG 202201)the Earmarked Fund for China Agriculture Research System(CARS-45).
文摘This study explores the potential of silver carp by-product hydrolysate(SCBH)as a sustainable and cost-effective alternative to mucin for cultivating Akkermansia muciniphila(Akk),a beneficial probiotic known to help prevent metabolic diseases like obesity,type II diabetes,and inflammatory bowel diseases.Traditionally,Akk relies on mucin in BHI medium,which is expensive and poses potential risks,including the transmission of swine influ-enza and restrictions due to religious considerations.We evaluated SCBH’s effects on Akk’s growth,morphology,and metabolic activity,focusing on short-chain fatty acids(SCFAs)production and the underlying mechanisms through which SCBH influences its growth and metabolism.Metabolomic analysis revealed that SCBH signifi-cantly(p<0.05)enhanced propionic,butyric,and isovaleric acid production by 19.05%,332.33%,and 35.88%,respectively.Additionally,SCBH promoted the synthesis of unsaturated fatty acid,supported amino acid metabolism,and increased taurine production while inhibiting ferroptosis,which may collectively enhancing Akk’s probiotic potential.SCBH also preserved Akk’s key morphological traits.These findings demonstrate SCBH’s efficacy as a mucin substitute,offering a novel and sustainable strategy for valorizing silver carp by-products and advancing Akk cultivation.This research provides mechanistic insights into SCBH’s role in opti-mizing Akk’s metabolic and functional properties.
