Objective Hepatitis Delt a Virus（HDV） antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for...Objective Hepatitis Delt a Virus（HDV） antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for this purpose. Methods Reconstruct the gene of HDV antigen based on the bias code of Escherichia coli, the recombinant protein expresses by high-density fermentation with fed-batch feeding strategy, and purify by immobilized metal chromatography. The sensitivity and specificity of this antigen detect by ELISA method. Results The expression of HDV antigen can reach 20% of the total cell mass in the soluble form. The recombinant HDV antigen can be conveniently purified（98%） by immobilized metal ion affinity chromatography（IMAC） using the interaction between a His-tag and nickel ions. Production of recombinant HDV antigen can reach 0.5 g/L under conditions of high-density cell fermentation. Applied to the diagnostic ELISA method, the recombinant HDV antigen shows excellent sensitivity（97% for IgM and 100% for IgG） and specificity（100% for IgG and IgM） for the detection of anti-HDV antibodies. Conclusion Expression and purification the recombinant HDV antigen as a candidate protein for application in a diagnostic ELISA for HDV infection. Large-scale production of the protein can be achieved using the high-density fermentation strategy.展开更多
Streptococcus thermophilus is a crucial microorganism in dairy fermentation.This study aimed to optimize its growth conditions and identify growth-related genes.Using strain S.thermophilus S-3,we developed a modified ...Streptococcus thermophilus is a crucial microorganism in dairy fermentation.This study aimed to optimize its growth conditions and identify growth-related genes.Using strain S.thermophilus S-3,we developed a modified medium through single-factor and orthogonal experiments based on LM17.The modified media formulations were:lactose 10 g/L,tryptone 5 g/L,soy peptone 5 g/L,yeast extract powder 10 g/L,beef extract powder 15 g/L,urea 4 g/L,and MgSO_(4)·7H_(2)O 1 g/L.Transcriptomics revealed differentially expressed genes under different culture conditions,which were subsequently overexpressed to assess their growth effects.The results showed that high-density fermentation of S.thermophilus is closely related to the TCA metabolic pathway,associated with the genes gltA,glnA,galK,and pgm.Our findings provide insights into the nutritional requirements and metabolic responses of S.thermophilus during high-density fermentation,advancing understanding of its growth and metabolic properties.展开更多
[Background]Surfactin is a biosurfactant with remarkable surface/interfacial activity.Surfactin production suffers from high costs of carbon sources and severe foaming problem during fermentation.Unreasonable utilizat...[Background]Surfactin is a biosurfactant with remarkable surface/interfacial activity.Surfactin production suffers from high costs of carbon sources and severe foaming problem during fermentation.Unreasonable utilization of soybean residue(okara)can cause resource waste and environmental pollution.[Objective]To achieve sustainable production of surfactin and valueadded conversion of okara,we explored foam-free production of surfactin by Bacillus subtilis using okara as a low-cost substrate and evaluated its application prospects.[Methods]We evaluated and compared the feasibility of B.subtilis utilizing okara to synthesize surfactin through liquid and solid-state fermentation methods.Biosurfactants were extracted from solid-state culture via a weak alkaline water extraction method.The products were identified by HPLC-MS,and the physicochemical properties of the produced surfactin were analyzed.The solid-state medium for fermentation of okara was optimized by the response surface method.The viable count of B.subtilis in solid-state fermentation residue was determined by the plate colony counting method.[Results]The conversion rates of okara to surfactin were 0.6%−0.8%and 1.2%−1.5%in liquid and solid-state fermentation,respectively.Interestingly,solid-state fermentation of okara by B.subtilis achieved both high-yield and foam-free production of surfactin.Five surfactin homologues were produced from okara,mainly including surfactin-C13(34.16%),surfactin-C_(14)(23.95%),and surfactin-C_(15)(35.14%).The produced surfactin,with a critical micelle concentration of 35.0 mg/L,decreased water surface tension to(26.0±0.1)mN/m and emulsified crude oil with emulsifying activity index(EI24)(73.1±3.2)%.It was stable at 4−121℃,pH 5.0−11.0,and NaCl<150 g/L.Okara,NH_(4)Cl,and CaCl_(2)·2H_(2)O were significant components in the solid-state medium.The surfactin yield was increased by 52.1%through solid-state medium optimization.Adding wheat straw further enhanced surfactin production by improving aeration in the solid-state medium.B.subtilis AnPL-1 produced(263.2±7.8)mg surfactin in the optimized solid-state medium containing 14.8 g okara and 1.5 g wheat straw.The conversion rate of okara to surfactin was enhanced to 1.8%.In addition,the residue of solid-state fermentation was expected to be microbial fertilizer since it contained 4.27×10^(10)CFU/g of B.subtilis.[Conclusion]This study established a promising way for foam-free production of surfactin and value-added conversion of okara.展开更多
Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels ...Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels are formed by nanophase separation of hydrophilic ion carriers and hydrophobic segments.It is difficult to realize high-density ion channels with controlled spatial arrangement and length scale of ion carriers.Herein,we construct high-density 1D ion wires as transmission channels.Through molecular design,hydrophilic imidazole groups and hydrophobic alkyl tails were introduced into the repeat units,which self-assembled into 1D ion transporting core and protecting shell along the main chains.The areal density of the ionic wire arrays is up to~10^(12)cm^(-2),which is the highest value.The ionic wires ensure both high ion flux transport and high selectivity,achieving an ultrahigh-power density of 40.5 W m^(-2)at a 500-fold salinity gradient.Besides,the ionic wire array membrane is well recyclable and antibacterial.The ionic wires provide novel concept for next generation of high-performance membranes.展开更多
Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive comp...Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive compounds,PRs are largely unexploited,with their management being an increasing concern for the pome-granate processing industry.The objective of this study was the development and characterization of a bio-process aiming at the biotechnological valorization of PRs for ethanol production.Specifically,a stepwise investigation was conducted,including(i)the production and chemical characterization of extracts/hydrolysates from PRs using distinct pretreatments not involving organic solvents or enzymatic hydrolysis;(ii)the assessment of the exploitability of a selected hydrolysate as fermentation feedstock using Saccharomyces cerevisiae;and(iii)the advancement of the bioprocess through the joined utilization in the fermentation substrate of PRs and seeded raisins(SRs),another important agro-industrial residue in Greece.The finally developed substrate,comprising a mixture of PRs/SRs extracts at concentrations 60/40%v/v,was used in three fermentation trials,and the fermentation process was quantitatively described using the Aiba model.The developed bioprocess resulted in satisfactorily high bioethanol production with the maximum attained concentration being 50.0±0.6 g/L.The maximum specific growth rate(μ_(max))of S.cerevisiae was estimated to be 0.1351/h and the bioethanol yield(Y_(ps)),namely the amount of produced ethanol/amount of consumed reducing sugars,was estimated to be 0.423 g/g.Hence,PRs can be efficiently used in the development of a fermentation substrate for bioethanol production,providing an economic and environmentally sustainable alternative to conventional feedstocks.展开更多
Environment serves as the pivotal medium to produce fermented food,with fluctuations in environmental factors exerting a profound impact on the modulation of fermentation microbial communities.Such shifts are crucial ...Environment serves as the pivotal medium to produce fermented food,with fluctuations in environmental factors exerting a profound impact on the modulation of fermentation microbial communities.Such shifts are crucial for the distinctiveness of fermented food flavor and the variability in quality.Chinese liquor(Baijiu)is one of the typical representatives of spontaneous fermented food.In this review,the multifaceted relationship between regional environmental attributes and the fermentation dynamics of Baijiu was examined,with a spotlight on the strong-flavor,sauce-flavor,and light-flavor varieties.It reveals the influence of regional environmental factors and brewing environmental factors on microbial function and metabolism,which results in the formation of unique flavor characteristics of Baijiu.The 9 main factors affecting the microecology of Baijiu fermentation were further explored,including environmental sensitivity,microbial interactions,biogeographic patterns,and key abiotic factors such as temperature and humidity.Environmental factor management is crucial for controlling microbial community in fermentation.Intelligent detection of the fermentation system is combined with artificial intelligence to realize the digitalization of Baijiu fermentation,with a view to further studying the environmental mechanism or quantitative control relationship of natural fermentation,improving the environmental stability of natural fermentation,and promoting the mechanization and intelligence of fermentation production.展开更多
The variation in microbiota during pit fermentation is the main reason for the distinct characteristics of the 7 types of base Baijiu in jiang-flavor Baijiu(JFB)brewing.However,the specific structure,succession,and fu...The variation in microbiota during pit fermentation is the main reason for the distinct characteristics of the 7 types of base Baijiu in jiang-flavor Baijiu(JFB)brewing.However,the specific structure,succession,and functional differentiation of microbial communities across different fermentation rounds remain unclear.Therefore,this study compared the differences in microbiota structure,environmental factors driving community assembly,and functional differentiations throughout 1–7 rounds(JC1–JC7)of pit fermentation in JFB production.Results showed that Lactobacillus dominated all rounds and complied with declining relative abundance from rounds JC1–JC7.The mould composition was similar in JC3–JC5 while the yeast structure in JC4 was found intermediate between JC3 and JC5.LEf Se analysis unveiled aroma-producing microorganisms as prominent biomarkers in JC1,strong enzyme-producing attributes in JC2,JC6,and JC7 biomarkers,and an enzyme and aroma-producing focus with robust tolerance in JC3–JC5 biomarkers.Acidity mainly regulated the microbial community in the first 4 rounds,with nutrient limitation drove microbial succession from the fifth round onward.Functional predictions underscored enriched amino acid metabolism enzymes in JC6 and JC1,while carbohydrate degradation exhibited predominant enzymatic profiles in JC2,JC6,and JC7.This study laid a foundation for comprehending community composition,succession,and flavor regulatory mechanisms throughout JFB brewing.展开更多
Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the undere...Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the underexplored medicinal potential of DF,we developed an efficient fermentation method to enhance the bioavailability of okara fiber.In this study,Pediococcus acidilactici IFJ-1,which has strong enzymatic production capabilities and beneficial effects on gastrointestinal flora modulation,was selected to ferment okara.Results showed decreases in viscosity and particle size,optimized surface structure,improved thermal stability and hydration properties,and a significant increase in soluble DF content from 1.85%to 3.91%.To evaluate the physiological effects,hyperlipidemic mouse models were established and subjected to dietary interventions utilizing okara and fermented okara to measure changes in physicochemical parameters,gut microbiota composition,and lipid metabolism.The dietary intervention was effective,particularly in the fermented okara group,showing a 7.3%weight loss,improved blood lipids(triglycerides:‒39.8%,total cholesterol:‒12.8%,low-density lipoprotein cholesterol:‒34.2%,high-density lipoprotein cholesterol:+26.2%),and a 22.2%lower liver index.Gut microbiota analysis revealed that fermented okara positively modulated the microbial community by increasing the abundance of beneficial bacteria(e.g.,Bacteroidota)and reducing the abundance of obesity-associated bacteria(e.g.,Bacillota).Lipid metabolism profiling further demonstrated that fermented okara downregulated harmful lipids(e.g.,(O-acyl)-ω-hydroxy fatty acids,ceramides,and diacylglycerols)while upregulating beneficial phospholipids(e.g.,phosphatidylinositol,phosphatidylserine,phosphatidylethanolamine,lysophosphatidylinositol and lysophosphatidic acid).This study highlights a novel approach for enhancing DF utilization through fermentation,providing valuable insights into strategies for preventing obesity and metabolic diseases.展开更多
To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subseq...To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.展开更多
Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship b...Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization,energy metabolism,and gut microbiota in growing pigs.Methods Thirty-six growing barrows(47.2±1.5 kg)were randomly allotted to 6 dietary treatments with 2 apparent viscosity levels and 3β-glucan-to-arabinoxylan ratios.In the experiment,nutrient utilization,energy metabolism,fecal microbial community,and production and absorption of short-chain fatty acid(SCFA)of pigs were investigated.In vitro digestion and fermentation models were used to compare the fermentation characteristics of feedstuffs and ileal digesta in the pig’s hindgut.Results The production dynamics of SCFA and dry matter corrected gas production of different feedstuffs during in vitro fermentation were different and closely related to the physical properties and chemical structure of the fiber.In animal experiments,increasing the dietary apparent viscosity and theβ-glucan-to-arabinoxylan ratios both increased the apparent ileal digestibility(AID),apparent total tract digestibility(ATTD),and hindgut digestibility of fiber components while decreasing the AID and ATTD of dry matter and organic matter(P<0.05).In addition,increasing dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased gas exchange,heat production,and protein oxidation,and decreased energy deposition(P<0.05).The dietary apparent viscosity andβ-glucanto-arabinoxylan ratios had linear interaction effects on the digestible energy,metabolizable energy,retained energy(RE),and net energy(NE)of the diets(P<0.05).At the same time,the increase of dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased SCFA production and absorption(P<0.05).Increasing the dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios increased the diversity and abundance of bacteria(P<0.05)and the relative abundance of beneficial bacteria.Furthermore,increasing the dietaryβ-glucan-to-arabinoxylan ratios led to a linear increase in SCFA production during the in vitro fermentation of ileal digesta(P<0.001).Finally,the prediction equations for RE and NE were established.Conclusion Dietary fiber physicochemical properties alter dietary fermentation patterns and regulate nutrient utilization,energy metabolism,and pig gut microbiota composition and metabolites.展开更多
Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant prod...Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant production performance.Our previous study identified significant differences in rumen microbial communities of Holstein calves with varying average daily gain(ADG).This study aims to identify a target strain based on the findings from multi-omics analysis and literature review,isolating and evaluating the target microbial strains from both the rumen and hindgut contents for their probiotic potential.Results Parabacteroides distasonis,a strain closely associated with ADG,was successfully isolated from calf rumen content cultured with Fastidious Anaerobe Agar(FAA)medium and named Parabacteroides distasonis F4.Wholegenome sequencing and pan-genome analysis showed that P.distasonis F4 possesses a core functional potential for carbohydrate and amino acid metabolism,with the ability to produce propionate,acetate,and lactate.The results of targeted and untargeted metabolomics further validated the organic acid production and metabolic pathways of P.distasonis F4.An in vitro simulated rumen fermentation test showed that supplementation with P.distasonis F4 significantly altered rumen microbial community structure and increased the molar proportions of propionate and butyrate in the rumen.Furthermore,an in vivo study demonstrated that dietary supplementation with P.distasonis F4 significantly increased the ADG of pre-weaning calves.Conclusions This study represents the first isolation of P.distasonis F4 from rumen,highlighting its potential as a probiotic strain for improving rumen development and growth performance in ruminants.展开更多
Cyclosporin A fermentation residue(CFR)is a type of organic waste generated during the production of cyclosporin A,which are abundant in nutrients including organic matter,phosphorus,nitrogen and potassium.Inappropria...Cyclosporin A fermentation residue(CFR)is a type of organic waste generated during the production of cyclosporin A,which are abundant in nutrients including organic matter,phosphorus,nitrogen and potassium.Inappropriate handling of CFR not only waste valuable bioresources,but may also lead to the cyclosporin A and associated resistance genes into the natural environment,posing a significant threat to ecological system and human health.Land application was an effective way to resource recovery of CFR after aerobic composting(CAC).This study investigated the impact of CAC on soil fertility and environmental safety.The results indicated that CAC could improve soil nutrient contents and enhance enzyme activities.CAC altered the diversity and community composition of soil bacteria,resulting in an increase in the abundance of relevant bacteria beneficial for organic matter decomposition and cyclosporin A degradation.The introduced cyclosporin A(71.69μg/kg)completely degraded within 20 days due to soil biodegradation.The significantly increased abundance of intIl,mdr3,pgp,TSR and pmra in the soil cultivation early stage were restored to the soil background level within 90 days,indicating a reduced risk of antimicrobial resistance.The results demonstrated that reasonable land application of CAC could improve soil fertility without antimicrobial resistance risk,which is helpful for evaluating the resource utilization value and environmental risks of antibiotic fermentation residue after aerobic composting.展开更多
In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA ...In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA production during the fermentation of soy sauce through Japanese-type(JP)and Cantonese-type(CP)processes were compared.BA analysis revealed that the most abundant BA species were putrescine,tyramine,and histamine in the later three stages(1187.68,785.16,and 193.20 mg/kg on average,respectively).The BA profiles differed significantly,with CP samples containing higher contents of putrescine,tyramine,and histamine(P<0.05)at the end of fermentation.Metagenomic analysis indicated that BA-producing genes exhibited different abundance profiles,with most genes,including spe A,spe B,arg,spe E,and tyr DC,having higher abundances in microbial communities during the CP process.In total,15 high-quality metagenome-assembled genomes(MAGs)were retrieved,of which 10 encoded at BA production-related genes.Enterococcus faecium(MAG10)and Weissella paramesenteroides(MAG5)might be the major tyramine producers.The high putrescine content in CP might be associated with the high abundance of Staphylococcus gallinarum(MAG8).This study provides a comprehensive understanding of the diversity and abundance of genes involved in BA synthesis,especially at the species level,during food fermentation.展开更多
In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentatio...In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentation broth were obtained and designated as SFB, Gly-SFB, and Glu-SFB, which were cultivated in beef protein medium and the beef protein medium supplemented with glycerol or glucose, respectively. The differences in antioxidant efficacy of SFB, Gly-SFB and Glu-SFB were investigated by evaluating intracellular ROS fluorescence intensity, SOD enzyme activity and MDA concentration. Gly-SFB and Glu-SFB exhibited a greater capacity to eliminate ROS as compared to that of SFB. The intracellular SOD enzyme activity increased as the concentrations of SFB and Gly-SFB increased. Nevertheless, the intracellular SOD enzyme activity was the highest after the treatment with Glu-SFB at the low concentrations. The intracellular MDA content reached a lower value after the treatment with Gly-SFB and Glu-SFB at lower concentrations, which was opposite to the case after the treatment with SFB. WB indicated that the S. epidermidis fermentation broth regulated the expression of relevant proteins in the Nrf2-Keap1 signaling pathway to exhibit the antioxidant effects. This indicates that the S. epidermidis fermentation broth promotes the expression of relevant proteins in the Nrf2-Keap1 signaling pathway, consequently, antioxidant benefits were exerted. The fermentation broth that were prepared by incorporating glycerol or glucose into the culture medium can augment their antioxidant activity.展开更多
Erythromycin fermentation residue(EFR)represents a typical hazardous waste produced by the microbial pharmaceutical industry.Although electrolysis is promising for EFR disposal,its microbial threats remain unclear.Her...Erythromycin fermentation residue(EFR)represents a typical hazardous waste produced by the microbial pharmaceutical industry.Although electrolysis is promising for EFR disposal,its microbial threats remain unclear.Herein,metagenomics was coupled with the random forest technique to decipher the antibiotic resistance patterns of electrochemically treated EFR.Results showed that 95.75%of erythromycin could be removed in 2 hr.Electrolysis temporarily influenced EFRmicrobiota,where the relative abundances of Proteobacteria and Actinobacteria increased,while those of Fusobacteria,Firmicutes,and Bacteroidetes decreased.A total of 505 antibiotic resistance gene(ARG)subtypes encoding resistance to 21 antibiotic types and 150 mobile genetic elements(MGEs),mainly including plasmid(72)and transposase(52)were assembled in EFR.Significant linear regression models were identified among microbial richness,ARG subtypes,and MGE numbers(r^(2)=0.50-0.81,p<0.001).Physicochemical factors of EFR(Total nitrogen,total organic carbon,protein,and humus)regulated ARG and MGE assembly(%IncMSE value=5.14-14.85).The core ARG,MGE,and microbe sets(93.08%-99.85%)successfully explained 89.71%-92.92%of total ARG and MGE abundances.Specifically,gene aph(3 )-I,transposase tnpA,and Mycolicibacterium were the primary drivers of the resistance dissemination system.This study also proposes efficient resistance mitigation measures,and provides recommendations for future management of antibiotic fermentation residue.展开更多
Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst an...Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst and the number of acceptable H*receptors.This study prepares highly dispersed Ni nanoparticles(NPs)catalysts on a Beta substrate via precursor structure topology transformation.In contrast to traditional support materials,the coordination and electronic structure changes between the Ni NPs and the support were achieved,further optimizing the active interface sites and enhancing hydrogen activation and hydrogenation performance.Additionally,the-OH groups at the strong acid sites in zeolite effectively intensified the hydrogen spillover effect as receptors for H^(*)migration and anchoring,accelerating the hydrogenation rate of aromatic rings.Under solvent-free conditions,this catalyst was used for the hydrogenation reaction of aromatic-rich oils,directly producing a C_(8)-C_(14)branched cycloalkanes mixture with an aromatic conversion rate of>99%.The cycloalkanes mixture produced by this method features high density(0.92 g/mL)and a low freezing point(<-60℃),making it suitable for use as high-density aviation fuel or as an additive to enhance the volumetric heat value of conventional aviation fuels in practical applications.展开更多
Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making ...Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making countries, presents a quality problem to the point of suffering a discount on the international market. One of these quality problems is the content of ochratoxin A, a mycotoxin produced by fungi. Finally, to verify the level of contamination in beans produced in Côte d’Ivoire, a study was carried out. It consisted of collecting information on fermentation and drying times (The two major post-harvest operations) and collecting beans, which were analyzed by electrophoresis using the High Performance Liquid Chromatography (HPLC) method. The results obtained show ochratoxin A contents of between 0.05 µg/kg and 0.17 µg/kg. The general level of contamination is therefore very low and below the tolerable limit which is 2 µg/kg. In addition, the correlative study between the fermentation and drying times of the beans revealed no significant influence (p < 0.01) of the duration of these operations on the level of ochratoxin A contamination. Major contamination can occur after post-harvest activities carried out by producers. This is certainly due to the development of fungi responsible for the production of ochratoxin A during the period of storage and marketing of cocoa beans in conditions of high humidity in storage enclosures. Producers need to be made more aware of the need to ensure that cocoa beans are properly dried and stored in dry areas to avoid moisture build-up, which is a source of mould growth and ochratoxin A production.展开更多
[Objectives]To explore the effects of fermentation process on the content and functions of flavonoids in Gardenia jasminoides.[Methods]G.jasminoides was fermented by microorganisms,and the fermentation process of tota...[Objectives]To explore the effects of fermentation process on the content and functions of flavonoids in Gardenia jasminoides.[Methods]G.jasminoides was fermented by microorganisms,and the fermentation process of total flavonoids from G.jasminoides was optimized,and the antioxidant activity and hyaluronidase inhibitory activity of the fermentation broth were tested.[Results]The best strain for fermentation of total flavonoids in G.jasminoides was Bacillus subtilis.The optimum fermentation conditions were as follows:the solid-liquid ratio was 1:30,the inoculation amount was 2%,and the fermentation time was 24 h.Under these fermentation conditions,the content of total flavonoids in G.jasminoides reached 36.90 mg/g,which was 45.22%higher than that of the control group without microbial fermentation,and it had good DPPH free radical and hydroxyl free radical scavenging ability,and the inhibition ability of hyaluronidase after fermentation was also improved.[Conclusions]This study provides a technical reference for the comprehensive application of G.jasminoides.展开更多
In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative ro...In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative rotary shear system(RSS)to address these deficiencies through controlled mandrel rotation and cooling rates.We successfully prepared self-reinforced HDPE pipes with a three-layer structure combining spherical and shish-kebab crystals.Rotational processing aligned the molecular chains in the ring direction and formed shish-kebab crystals.As a result,the annular tensile strength of the rotationally processed three-layer shish-kebab structure(TSK)pipe increased from 26.7 MPa to 76.3 MPa,an enhancement of 185.8%.Notably,while maintaining excellent tensile strength(73.4 MPa),the elongation at break of the spherulite shishkebab spherulite(SKS)tubes was improved to 50.1%,as compared to 33.8%in the case of shish-kebab spherulite shish-kebab(KSK)tubes.This improvement can be attributed to the changes in the micro-morphology and polymer structure within the SKS tubes,specifically due to the formation of small-sized shish-kebab crystals and the low degrees of interlocking.In addition,2D-SAXS analysis revealed that KSK tubes have higher tensile strength due to smaller crystal sizes and larger shish dimensions,forming dense interlocking structures.In contrast,the SKS and TSK tubes had thicker amorphous regions and smaller shish sizes,resulting in reduced interlocking and mechanical performance.展开更多
Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries,providing a scientific basis for subsequent greening efforts.Backfil...Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries,providing a scientific basis for subsequent greening efforts.Backfill soil,predominantly composed of silty clay,demonstrates high water retention capacity and elevated moisture content,leading to a pronounced resistivity contrast with the bedrock exposed by quarrying activities.To investigate the distribution of backfill soil subsurface and assess backfilling effectiveness in the study area,this study conducted a comprehensive geophysical investigation utilizing the high-density electrical resistivity tomography(ERT).A total of 19 ERT survey lines were deployed across three distinct areas in Liuyao Village,Huaibei City,Anhui Province,China.The inversion results,derived from both two-dimensional(2D)and three-dimensional(3D),reveal distinct electrical properties of the subsurface materials:the backfill soil layer shows low resistivity features,the fill stone layer exhibits medium to high resistivity,and the bedrock shows the highest resistivity.The 2D inversion results,from the data measured using the Wenner array effectively capture the spatial distribution and structural features of the backfill soil layer.The findings indicate a gradual east-west thinning of the clay layer within the quarry.Furthermore,the northern pit area exhibits a uniform distribution of backfill soil layer,indicative of effective backfilling operations.In contrast,the southern pit area lacks a well-defined clay layer,suggesting suboptimal backfilling effectiveness.展开更多
文摘Objective Hepatitis Delt a Virus（HDV） antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for this purpose. Methods Reconstruct the gene of HDV antigen based on the bias code of Escherichia coli, the recombinant protein expresses by high-density fermentation with fed-batch feeding strategy, and purify by immobilized metal chromatography. The sensitivity and specificity of this antigen detect by ELISA method. Results The expression of HDV antigen can reach 20% of the total cell mass in the soluble form. The recombinant HDV antigen can be conveniently purified（98%） by immobilized metal ion affinity chromatography（IMAC） using the interaction between a His-tag and nickel ions. Production of recombinant HDV antigen can reach 0.5 g/L under conditions of high-density cell fermentation. Applied to the diagnostic ELISA method, the recombinant HDV antigen shows excellent sensitivity（97% for IgM and 100% for IgG） and specificity（100% for IgG and IgM） for the detection of anti-HDV antibodies. Conclusion Expression and purification the recombinant HDV antigen as a candidate protein for application in a diagnostic ELISA for HDV infection. Large-scale production of the protein can be achieved using the high-density fermentation strategy.
基金supported by National Natural Science Foundation of China(grant No.32272300)National Science Foundation for Distinguished Young Scholars(grant No.32025029)+2 种基金Shanghai Education committee scientific research innovation projects,China(grant No.2101070007800120)the National Natural Science Foundation of China(U23A20261)the Shanghai Engineering Research Center of food microbiology program(grant No.19DZ2281100).
文摘Streptococcus thermophilus is a crucial microorganism in dairy fermentation.This study aimed to optimize its growth conditions and identify growth-related genes.Using strain S.thermophilus S-3,we developed a modified medium through single-factor and orthogonal experiments based on LM17.The modified media formulations were:lactose 10 g/L,tryptone 5 g/L,soy peptone 5 g/L,yeast extract powder 10 g/L,beef extract powder 15 g/L,urea 4 g/L,and MgSO_(4)·7H_(2)O 1 g/L.Transcriptomics revealed differentially expressed genes under different culture conditions,which were subsequently overexpressed to assess their growth effects.The results showed that high-density fermentation of S.thermophilus is closely related to the TCA metabolic pathway,associated with the genes gltA,glnA,galK,and pgm.Our findings provide insights into the nutritional requirements and metabolic responses of S.thermophilus during high-density fermentation,advancing understanding of its growth and metabolic properties.
基金supported by the Research Start-up Foundation for Introduced Talent of Qufu Normal University(609601)。
文摘[Background]Surfactin is a biosurfactant with remarkable surface/interfacial activity.Surfactin production suffers from high costs of carbon sources and severe foaming problem during fermentation.Unreasonable utilization of soybean residue(okara)can cause resource waste and environmental pollution.[Objective]To achieve sustainable production of surfactin and valueadded conversion of okara,we explored foam-free production of surfactin by Bacillus subtilis using okara as a low-cost substrate and evaluated its application prospects.[Methods]We evaluated and compared the feasibility of B.subtilis utilizing okara to synthesize surfactin through liquid and solid-state fermentation methods.Biosurfactants were extracted from solid-state culture via a weak alkaline water extraction method.The products were identified by HPLC-MS,and the physicochemical properties of the produced surfactin were analyzed.The solid-state medium for fermentation of okara was optimized by the response surface method.The viable count of B.subtilis in solid-state fermentation residue was determined by the plate colony counting method.[Results]The conversion rates of okara to surfactin were 0.6%−0.8%and 1.2%−1.5%in liquid and solid-state fermentation,respectively.Interestingly,solid-state fermentation of okara by B.subtilis achieved both high-yield and foam-free production of surfactin.Five surfactin homologues were produced from okara,mainly including surfactin-C13(34.16%),surfactin-C_(14)(23.95%),and surfactin-C_(15)(35.14%).The produced surfactin,with a critical micelle concentration of 35.0 mg/L,decreased water surface tension to(26.0±0.1)mN/m and emulsified crude oil with emulsifying activity index(EI24)(73.1±3.2)%.It was stable at 4−121℃,pH 5.0−11.0,and NaCl<150 g/L.Okara,NH_(4)Cl,and CaCl_(2)·2H_(2)O were significant components in the solid-state medium.The surfactin yield was increased by 52.1%through solid-state medium optimization.Adding wheat straw further enhanced surfactin production by improving aeration in the solid-state medium.B.subtilis AnPL-1 produced(263.2±7.8)mg surfactin in the optimized solid-state medium containing 14.8 g okara and 1.5 g wheat straw.The conversion rate of okara to surfactin was enhanced to 1.8%.In addition,the residue of solid-state fermentation was expected to be microbial fertilizer since it contained 4.27×10^(10)CFU/g of B.subtilis.[Conclusion]This study established a promising way for foam-free production of surfactin and value-added conversion of okara.
基金financially supported by the Key R&D Program of Shandong Province(2022SFGC0801)the National Natural Science Foundation of China(No.22005162 and 22175009)the Natural Science Foundation of Shandong Province(No.ZR2020QE093)。
文摘Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels are formed by nanophase separation of hydrophilic ion carriers and hydrophobic segments.It is difficult to realize high-density ion channels with controlled spatial arrangement and length scale of ion carriers.Herein,we construct high-density 1D ion wires as transmission channels.Through molecular design,hydrophilic imidazole groups and hydrophobic alkyl tails were introduced into the repeat units,which self-assembled into 1D ion transporting core and protecting shell along the main chains.The areal density of the ionic wire arrays is up to~10^(12)cm^(-2),which is the highest value.The ionic wires ensure both high ion flux transport and high selectivity,achieving an ultrahigh-power density of 40.5 W m^(-2)at a 500-fold salinity gradient.Besides,the ionic wire array membrane is well recyclable and antibacterial.The ionic wires provide novel concept for next generation of high-performance membranes.
基金financed by the Green Fund of the Hellenic Ministry of Environment and Energy,under the funding program“National Environment and Innovation Activities 2022”,Priority Axis“Research&Application”,Project“Sustainable technology for converting pomegranate residues into bioproducts and bioactive compounds”with the acronym“POMEGRANATE”.
文摘Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive compounds,PRs are largely unexploited,with their management being an increasing concern for the pome-granate processing industry.The objective of this study was the development and characterization of a bio-process aiming at the biotechnological valorization of PRs for ethanol production.Specifically,a stepwise investigation was conducted,including(i)the production and chemical characterization of extracts/hydrolysates from PRs using distinct pretreatments not involving organic solvents or enzymatic hydrolysis;(ii)the assessment of the exploitability of a selected hydrolysate as fermentation feedstock using Saccharomyces cerevisiae;and(iii)the advancement of the bioprocess through the joined utilization in the fermentation substrate of PRs and seeded raisins(SRs),another important agro-industrial residue in Greece.The finally developed substrate,comprising a mixture of PRs/SRs extracts at concentrations 60/40%v/v,was used in three fermentation trials,and the fermentation process was quantitatively described using the Aiba model.The developed bioprocess resulted in satisfactorily high bioethanol production with the maximum attained concentration being 50.0±0.6 g/L.The maximum specific growth rate(μ_(max))of S.cerevisiae was estimated to be 0.1351/h and the bioethanol yield(Y_(ps)),namely the amount of produced ethanol/amount of consumed reducing sugars,was estimated to be 0.423 g/g.Hence,PRs can be efficiently used in the development of a fermentation substrate for bioethanol production,providing an economic and environmentally sustainable alternative to conventional feedstocks.
基金financially supported by the National Natural Science Foundation of China(22138004)National Treasure Ecological Research Synergetic Innovation Center.
文摘Environment serves as the pivotal medium to produce fermented food,with fluctuations in environmental factors exerting a profound impact on the modulation of fermentation microbial communities.Such shifts are crucial for the distinctiveness of fermented food flavor and the variability in quality.Chinese liquor(Baijiu)is one of the typical representatives of spontaneous fermented food.In this review,the multifaceted relationship between regional environmental attributes and the fermentation dynamics of Baijiu was examined,with a spotlight on the strong-flavor,sauce-flavor,and light-flavor varieties.It reveals the influence of regional environmental factors and brewing environmental factors on microbial function and metabolism,which results in the formation of unique flavor characteristics of Baijiu.The 9 main factors affecting the microecology of Baijiu fermentation were further explored,including environmental sensitivity,microbial interactions,biogeographic patterns,and key abiotic factors such as temperature and humidity.Environmental factor management is crucial for controlling microbial community in fermentation.Intelligent detection of the fermentation system is combined with artificial intelligence to realize the digitalization of Baijiu fermentation,with a view to further studying the environmental mechanism or quantitative control relationship of natural fermentation,improving the environmental stability of natural fermentation,and promoting the mechanization and intelligence of fermentation production.
文摘The variation in microbiota during pit fermentation is the main reason for the distinct characteristics of the 7 types of base Baijiu in jiang-flavor Baijiu(JFB)brewing.However,the specific structure,succession,and functional differentiation of microbial communities across different fermentation rounds remain unclear.Therefore,this study compared the differences in microbiota structure,environmental factors driving community assembly,and functional differentiations throughout 1–7 rounds(JC1–JC7)of pit fermentation in JFB production.Results showed that Lactobacillus dominated all rounds and complied with declining relative abundance from rounds JC1–JC7.The mould composition was similar in JC3–JC5 while the yeast structure in JC4 was found intermediate between JC3 and JC5.LEf Se analysis unveiled aroma-producing microorganisms as prominent biomarkers in JC1,strong enzyme-producing attributes in JC2,JC6,and JC7 biomarkers,and an enzyme and aroma-producing focus with robust tolerance in JC3–JC5 biomarkers.Acidity mainly regulated the microbial community in the first 4 rounds,with nutrient limitation drove microbial succession from the fifth round onward.Functional predictions underscored enriched amino acid metabolism enzymes in JC6 and JC1,while carbohydrate degradation exhibited predominant enzymatic profiles in JC2,JC6,and JC7.This study laid a foundation for comprehending community composition,succession,and flavor regulatory mechanisms throughout JFB brewing.
基金supported by the Key Special Projects of the Ministry of Science and Technology(SQ2020YFF0404523)the North Anhui Soybean Advantageous Characteristic Industry Cluster Project(2023CYJQ013)+2 种基金the National Natural Science Foundation of China(32172162)the Key Genetic Technologies Research and Development Program of Hefei(2021GJ075)the Young Talents Program of Anhui Academy of Agricultural Science(QNYC-202122).
文摘Okara is produced in large quantities annually in China,but much of it is discarded due to its high content of indigestible dietary fiber(DF),contributing to significant environmental challenges.Recognizing the underexplored medicinal potential of DF,we developed an efficient fermentation method to enhance the bioavailability of okara fiber.In this study,Pediococcus acidilactici IFJ-1,which has strong enzymatic production capabilities and beneficial effects on gastrointestinal flora modulation,was selected to ferment okara.Results showed decreases in viscosity and particle size,optimized surface structure,improved thermal stability and hydration properties,and a significant increase in soluble DF content from 1.85%to 3.91%.To evaluate the physiological effects,hyperlipidemic mouse models were established and subjected to dietary interventions utilizing okara and fermented okara to measure changes in physicochemical parameters,gut microbiota composition,and lipid metabolism.The dietary intervention was effective,particularly in the fermented okara group,showing a 7.3%weight loss,improved blood lipids(triglycerides:‒39.8%,total cholesterol:‒12.8%,low-density lipoprotein cholesterol:‒34.2%,high-density lipoprotein cholesterol:+26.2%),and a 22.2%lower liver index.Gut microbiota analysis revealed that fermented okara positively modulated the microbial community by increasing the abundance of beneficial bacteria(e.g.,Bacteroidota)and reducing the abundance of obesity-associated bacteria(e.g.,Bacillota).Lipid metabolism profiling further demonstrated that fermented okara downregulated harmful lipids(e.g.,(O-acyl)-ω-hydroxy fatty acids,ceramides,and diacylglycerols)while upregulating beneficial phospholipids(e.g.,phosphatidylinositol,phosphatidylserine,phosphatidylethanolamine,lysophosphatidylinositol and lysophosphatidic acid).This study highlights a novel approach for enhancing DF utilization through fermentation,providing valuable insights into strategies for preventing obesity and metabolic diseases.
文摘To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.
基金supported by the National Key Research and Development Program(No.2021YFD1300201)Jilin Provincial Department of Science and Technology Innovation Platform and Talent Special Project(No.20230508090RC).
文摘Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization,energy metabolism,and gut microbiota in growing pigs.Methods Thirty-six growing barrows(47.2±1.5 kg)were randomly allotted to 6 dietary treatments with 2 apparent viscosity levels and 3β-glucan-to-arabinoxylan ratios.In the experiment,nutrient utilization,energy metabolism,fecal microbial community,and production and absorption of short-chain fatty acid(SCFA)of pigs were investigated.In vitro digestion and fermentation models were used to compare the fermentation characteristics of feedstuffs and ileal digesta in the pig’s hindgut.Results The production dynamics of SCFA and dry matter corrected gas production of different feedstuffs during in vitro fermentation were different and closely related to the physical properties and chemical structure of the fiber.In animal experiments,increasing the dietary apparent viscosity and theβ-glucan-to-arabinoxylan ratios both increased the apparent ileal digestibility(AID),apparent total tract digestibility(ATTD),and hindgut digestibility of fiber components while decreasing the AID and ATTD of dry matter and organic matter(P<0.05).In addition,increasing dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased gas exchange,heat production,and protein oxidation,and decreased energy deposition(P<0.05).The dietary apparent viscosity andβ-glucanto-arabinoxylan ratios had linear interaction effects on the digestible energy,metabolizable energy,retained energy(RE),and net energy(NE)of the diets(P<0.05).At the same time,the increase of dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased SCFA production and absorption(P<0.05).Increasing the dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios increased the diversity and abundance of bacteria(P<0.05)and the relative abundance of beneficial bacteria.Furthermore,increasing the dietaryβ-glucan-to-arabinoxylan ratios led to a linear increase in SCFA production during the in vitro fermentation of ileal digesta(P<0.001).Finally,the prediction equations for RE and NE were established.Conclusion Dietary fiber physicochemical properties alter dietary fermentation patterns and regulate nutrient utilization,energy metabolism,and pig gut microbiota composition and metabolites.
基金funded by National Key Research and Development Program(2022YFA1304200)Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2023-IFR-04 and CAAS-ZDRW202305)the Beijing Innovation Consortium of Livestock Research System(BAIC05-2023).
文摘Background Rumen microorganisms are key regulators of ruminant growth and production performance.Identifying probiotic candidates through microbial culturomics presents a promising strategy for improving ruminant production performance.Our previous study identified significant differences in rumen microbial communities of Holstein calves with varying average daily gain(ADG).This study aims to identify a target strain based on the findings from multi-omics analysis and literature review,isolating and evaluating the target microbial strains from both the rumen and hindgut contents for their probiotic potential.Results Parabacteroides distasonis,a strain closely associated with ADG,was successfully isolated from calf rumen content cultured with Fastidious Anaerobe Agar(FAA)medium and named Parabacteroides distasonis F4.Wholegenome sequencing and pan-genome analysis showed that P.distasonis F4 possesses a core functional potential for carbohydrate and amino acid metabolism,with the ability to produce propionate,acetate,and lactate.The results of targeted and untargeted metabolomics further validated the organic acid production and metabolic pathways of P.distasonis F4.An in vitro simulated rumen fermentation test showed that supplementation with P.distasonis F4 significantly altered rumen microbial community structure and increased the molar proportions of propionate and butyrate in the rumen.Furthermore,an in vivo study demonstrated that dietary supplementation with P.distasonis F4 significantly increased the ADG of pre-weaning calves.Conclusions This study represents the first isolation of P.distasonis F4 from rumen,highlighting its potential as a probiotic strain for improving rumen development and growth performance in ruminants.
基金supported by the National Natural Science Foundation of China(No.52170138)the National Key Research and Development Program of China(No.2023YFD1900305)+3 种基金Qingdao Agricultural University Doctoral Start-Up Fund(No.6631122003)the Project of Talent IntroductionEducation Program of Youth Innovation Teams in Universities of Shandong Province(2021–05)Shandong Provincial College Youth Innovation Team Program(No.2023KJ169).
文摘Cyclosporin A fermentation residue(CFR)is a type of organic waste generated during the production of cyclosporin A,which are abundant in nutrients including organic matter,phosphorus,nitrogen and potassium.Inappropriate handling of CFR not only waste valuable bioresources,but may also lead to the cyclosporin A and associated resistance genes into the natural environment,posing a significant threat to ecological system and human health.Land application was an effective way to resource recovery of CFR after aerobic composting(CAC).This study investigated the impact of CAC on soil fertility and environmental safety.The results indicated that CAC could improve soil nutrient contents and enhance enzyme activities.CAC altered the diversity and community composition of soil bacteria,resulting in an increase in the abundance of relevant bacteria beneficial for organic matter decomposition and cyclosporin A degradation.The introduced cyclosporin A(71.69μg/kg)completely degraded within 20 days due to soil biodegradation.The significantly increased abundance of intIl,mdr3,pgp,TSR and pmra in the soil cultivation early stage were restored to the soil background level within 90 days,indicating a reduced risk of antimicrobial resistance.The results demonstrated that reasonable land application of CAC could improve soil fertility without antimicrobial resistance risk,which is helpful for evaluating the resource utilization value and environmental risks of antibiotic fermentation residue after aerobic composting.
基金supported by the Natural Science Foundation of Guangdong Province(2022A1515012158)the National Science Foundation of China(41977138)+3 种基金the Construction Project of Teaching Quality and Teaching Reform in Guangdong Province(SJD202001)the General University Project of Guangdong Provincial Department of Education(2021KCXTD070 and 2021ZDZX4072)the Key Project of Social Welfare and Basic Research of Zhongshan City(2020B2010)the Start-up Fund from the Zhongshan Institute at the University of Electronic Science and Technology in China(419YKQN12)。
文摘In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA production during the fermentation of soy sauce through Japanese-type(JP)and Cantonese-type(CP)processes were compared.BA analysis revealed that the most abundant BA species were putrescine,tyramine,and histamine in the later three stages(1187.68,785.16,and 193.20 mg/kg on average,respectively).The BA profiles differed significantly,with CP samples containing higher contents of putrescine,tyramine,and histamine(P<0.05)at the end of fermentation.Metagenomic analysis indicated that BA-producing genes exhibited different abundance profiles,with most genes,including spe A,spe B,arg,spe E,and tyr DC,having higher abundances in microbial communities during the CP process.In total,15 high-quality metagenome-assembled genomes(MAGs)were retrieved,of which 10 encoded at BA production-related genes.Enterococcus faecium(MAG10)and Weissella paramesenteroides(MAG5)might be the major tyramine producers.The high putrescine content in CP might be associated with the high abundance of Staphylococcus gallinarum(MAG8).This study provides a comprehensive understanding of the diversity and abundance of genes involved in BA synthesis,especially at the species level,during food fermentation.
文摘In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentation broth were obtained and designated as SFB, Gly-SFB, and Glu-SFB, which were cultivated in beef protein medium and the beef protein medium supplemented with glycerol or glucose, respectively. The differences in antioxidant efficacy of SFB, Gly-SFB and Glu-SFB were investigated by evaluating intracellular ROS fluorescence intensity, SOD enzyme activity and MDA concentration. Gly-SFB and Glu-SFB exhibited a greater capacity to eliminate ROS as compared to that of SFB. The intracellular SOD enzyme activity increased as the concentrations of SFB and Gly-SFB increased. Nevertheless, the intracellular SOD enzyme activity was the highest after the treatment with Glu-SFB at the low concentrations. The intracellular MDA content reached a lower value after the treatment with Gly-SFB and Glu-SFB at lower concentrations, which was opposite to the case after the treatment with SFB. WB indicated that the S. epidermidis fermentation broth regulated the expression of relevant proteins in the Nrf2-Keap1 signaling pathway to exhibit the antioxidant effects. This indicates that the S. epidermidis fermentation broth promotes the expression of relevant proteins in the Nrf2-Keap1 signaling pathway, consequently, antioxidant benefits were exerted. The fermentation broth that were prepared by incorporating glycerol or glucose into the culture medium can augment their antioxidant activity.
基金supported by the Special Project of Basic Scientific Research Business of Central Public Welfare Scientific Research Institutes (No.2019YSKY-027).
文摘Erythromycin fermentation residue(EFR)represents a typical hazardous waste produced by the microbial pharmaceutical industry.Although electrolysis is promising for EFR disposal,its microbial threats remain unclear.Herein,metagenomics was coupled with the random forest technique to decipher the antibiotic resistance patterns of electrochemically treated EFR.Results showed that 95.75%of erythromycin could be removed in 2 hr.Electrolysis temporarily influenced EFRmicrobiota,where the relative abundances of Proteobacteria and Actinobacteria increased,while those of Fusobacteria,Firmicutes,and Bacteroidetes decreased.A total of 505 antibiotic resistance gene(ARG)subtypes encoding resistance to 21 antibiotic types and 150 mobile genetic elements(MGEs),mainly including plasmid(72)and transposase(52)were assembled in EFR.Significant linear regression models were identified among microbial richness,ARG subtypes,and MGE numbers(r^(2)=0.50-0.81,p<0.001).Physicochemical factors of EFR(Total nitrogen,total organic carbon,protein,and humus)regulated ARG and MGE assembly(%IncMSE value=5.14-14.85).The core ARG,MGE,and microbe sets(93.08%-99.85%)successfully explained 89.71%-92.92%of total ARG and MGE abundances.Specifically,gene aph(3 )-I,transposase tnpA,and Mycolicibacterium were the primary drivers of the resistance dissemination system.This study also proposes efficient resistance mitigation measures,and provides recommendations for future management of antibiotic fermentation residue.
基金financially supported by the National Natural Science Foundation of China(Grant 22278439,21776313)the Shandong Province Higher Education Youth Innovation Technology Support Program(Grant 2022KJ074)。
文摘Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst and the number of acceptable H*receptors.This study prepares highly dispersed Ni nanoparticles(NPs)catalysts on a Beta substrate via precursor structure topology transformation.In contrast to traditional support materials,the coordination and electronic structure changes between the Ni NPs and the support were achieved,further optimizing the active interface sites and enhancing hydrogen activation and hydrogenation performance.Additionally,the-OH groups at the strong acid sites in zeolite effectively intensified the hydrogen spillover effect as receptors for H^(*)migration and anchoring,accelerating the hydrogenation rate of aromatic rings.Under solvent-free conditions,this catalyst was used for the hydrogenation reaction of aromatic-rich oils,directly producing a C_(8)-C_(14)branched cycloalkanes mixture with an aromatic conversion rate of>99%.The cycloalkanes mixture produced by this method features high density(0.92 g/mL)and a low freezing point(<-60℃),making it suitable for use as high-density aviation fuel or as an additive to enhance the volumetric heat value of conventional aviation fuels in practical applications.
文摘Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making countries, presents a quality problem to the point of suffering a discount on the international market. One of these quality problems is the content of ochratoxin A, a mycotoxin produced by fungi. Finally, to verify the level of contamination in beans produced in Côte d’Ivoire, a study was carried out. It consisted of collecting information on fermentation and drying times (The two major post-harvest operations) and collecting beans, which were analyzed by electrophoresis using the High Performance Liquid Chromatography (HPLC) method. The results obtained show ochratoxin A contents of between 0.05 µg/kg and 0.17 µg/kg. The general level of contamination is therefore very low and below the tolerable limit which is 2 µg/kg. In addition, the correlative study between the fermentation and drying times of the beans revealed no significant influence (p < 0.01) of the duration of these operations on the level of ochratoxin A contamination. Major contamination can occur after post-harvest activities carried out by producers. This is certainly due to the development of fungi responsible for the production of ochratoxin A during the period of storage and marketing of cocoa beans in conditions of high humidity in storage enclosures. Producers need to be made more aware of the need to ensure that cocoa beans are properly dried and stored in dry areas to avoid moisture build-up, which is a source of mould growth and ochratoxin A production.
基金Supported by Shanghai Putuo District R&D Platform Project(2024QX04).
文摘[Objectives]To explore the effects of fermentation process on the content and functions of flavonoids in Gardenia jasminoides.[Methods]G.jasminoides was fermented by microorganisms,and the fermentation process of total flavonoids from G.jasminoides was optimized,and the antioxidant activity and hyaluronidase inhibitory activity of the fermentation broth were tested.[Results]The best strain for fermentation of total flavonoids in G.jasminoides was Bacillus subtilis.The optimum fermentation conditions were as follows:the solid-liquid ratio was 1:30,the inoculation amount was 2%,and the fermentation time was 24 h.Under these fermentation conditions,the content of total flavonoids in G.jasminoides reached 36.90 mg/g,which was 45.22%higher than that of the control group without microbial fermentation,and it had good DPPH free radical and hydroxyl free radical scavenging ability,and the inhibition ability of hyaluronidase after fermentation was also improved.[Conclusions]This study provides a technical reference for the comprehensive application of G.jasminoides.
基金supported by the National Natural Science Foundation of China(Nos.52373045 and 52033005).
文摘In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative rotary shear system(RSS)to address these deficiencies through controlled mandrel rotation and cooling rates.We successfully prepared self-reinforced HDPE pipes with a three-layer structure combining spherical and shish-kebab crystals.Rotational processing aligned the molecular chains in the ring direction and formed shish-kebab crystals.As a result,the annular tensile strength of the rotationally processed three-layer shish-kebab structure(TSK)pipe increased from 26.7 MPa to 76.3 MPa,an enhancement of 185.8%.Notably,while maintaining excellent tensile strength(73.4 MPa),the elongation at break of the spherulite shishkebab spherulite(SKS)tubes was improved to 50.1%,as compared to 33.8%in the case of shish-kebab spherulite shish-kebab(KSK)tubes.This improvement can be attributed to the changes in the micro-morphology and polymer structure within the SKS tubes,specifically due to the formation of small-sized shish-kebab crystals and the low degrees of interlocking.In addition,2D-SAXS analysis revealed that KSK tubes have higher tensile strength due to smaller crystal sizes and larger shish dimensions,forming dense interlocking structures.In contrast,the SKS and TSK tubes had thicker amorphous regions and smaller shish sizes,resulting in reduced interlocking and mechanical performance.
基金Supported by National Key Research and Development Program of China(No.2023YFC3707901)。
文摘Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries,providing a scientific basis for subsequent greening efforts.Backfill soil,predominantly composed of silty clay,demonstrates high water retention capacity and elevated moisture content,leading to a pronounced resistivity contrast with the bedrock exposed by quarrying activities.To investigate the distribution of backfill soil subsurface and assess backfilling effectiveness in the study area,this study conducted a comprehensive geophysical investigation utilizing the high-density electrical resistivity tomography(ERT).A total of 19 ERT survey lines were deployed across three distinct areas in Liuyao Village,Huaibei City,Anhui Province,China.The inversion results,derived from both two-dimensional(2D)and three-dimensional(3D),reveal distinct electrical properties of the subsurface materials:the backfill soil layer shows low resistivity features,the fill stone layer exhibits medium to high resistivity,and the bedrock shows the highest resistivity.The 2D inversion results,from the data measured using the Wenner array effectively capture the spatial distribution and structural features of the backfill soil layer.The findings indicate a gradual east-west thinning of the clay layer within the quarry.Furthermore,the northern pit area exhibits a uniform distribution of backfill soil layer,indicative of effective backfilling operations.In contrast,the southern pit area lacks a well-defined clay layer,suggesting suboptimal backfilling effectiveness.
