In order to grasp the distribution of Aspergillus flavus in the soil of peanut production areas in China,A.flavus biomarkers were tested on 555 soil samples from 37 sampling points in 17 provinces,peanut fields in fou...In order to grasp the distribution of Aspergillus flavus in the soil of peanut production areas in China,A.flavus biomarkers were tested on 555 soil samples from 37 sampling points in 17 provinces,peanut fields in four agroecological zones(Southern area,Yangtze River Basin,Northern area,Northeast area).The results showed that(1)the cultivation amount of A.flavus per gram of soil in the Yangtze River Basin is 1.30 times that of the southern area,1.56 times that of the northern area,and 6.20 times that of the northeast area,with obvious regional characteristics.(2)In the Yangtze River basin,the change of longitude in the east-west direction has no direct impact on the cultivation amount of A.flavus per gram of soil.(3)In the east coast,the A.flavus cultivated per gram of soil increased first and then decreased with the increase of latitude from south to north.(4)A.flavus can be isolated in the soil samples above 1000 m.Field pollution is an important source of aflatoxin contamination in peanut.The study on the distribution of A.flavus in soil in China could provide theoretical support for the early warning and prevention and control measures of aflatoxin contamination in peanut.展开更多
Maize (Zea mays L.), one of main crops in the world, is easily susceptible to Aspergillusflavus (Link: fr) infection, resulting huge loses worldwide. Breeding for A. flavus resistance has been proved an efficient...Maize (Zea mays L.), one of main crops in the world, is easily susceptible to Aspergillusflavus (Link: fr) infection, resulting huge loses worldwide. Breeding for A. flavus resistance has been proved an efficient way to solve the problem of aflatoxin contamination. Genetic analysis of the sources of resistance to A.flavus in maize is necessary for this purpose. The complete diallel crosses of 6 inbred lines with different resistance to A.flavus infection were implemented. Inoculation categorical data of each cross were analyzed with the additive-dominant and additive-dominant-epitasis genetic models. Results indicated some crosses fitted the 2 major genes with additive-dominant-epitasis genetic model. Others fitted the major gene and polygene mixed model. Moreover, the additive, dominant, and epitasis effects varied in crosses. The A.flavus resistance was controlled by both major gene and polygene.展开更多
To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-meth...To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-methoxybenzaldehyde)and the possible antifungal mechanisms have been investigated.All the four volatile aldehydes could inhibit the germination of spores,and the minimum inhibitory concentrations(MICs)of them were in this order:vanillin(200μg/mL),o-vanillin(100μg/mL),2-hydroxy-5-methoxybenzaldehyde(100μg/mL),HMB(70μg/mL).The minimum fungicidal concentrations(MFCs)of them were in this order:vanillin(240μg/mL),o-vanillin(160μg/mL),HMB(140μg/mL),2-hydroxy-5-methoxybenzaldehyde(140μg/mL).Spore size was arrested at 0 h with the treatment of the four volatile aldehydes.Effects of the four volatile aldehydes on the cell wall and cell membrane integrity of A flavus were observed by calcofluor white(CW)staining and propidium iodide(PI)staining.The results showed that HMB exerted the strongest antifungal and fungicidal effects on the growth of A.flavus.The four volatile aldehydes had little influence on cell wall integrity after 3-hour treatment,however,they could strongly damage the cell membrane integrity.All the four volatile aldehydes could effectively prevent the growth of A.flavus on peanut seeds.The antifungal mechanisms of the four volatile aldehydes provide theoretical foundations for their development of new antifungal agents.展开更多
In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy io...In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy ion beam implantation is a new tool for breeding excellent mutant strains. In this study, the ion beam implantation experiments were performed by infusing two different ions: argon ion (Ar^+) and nitrogen ion (N^+). The results showed that the optimal ion implantation was N^+ with an optimum dose of 2.08- 1015 ions/cm^2, with which the mutant strain AF-ANm16 that produced no red pigment was obtained. The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation, which could be utilized in industrial fermentation. The differences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA (RAPD). The results indicated that the frequency of variation was 7.00%, which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation.展开更多
The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis ...The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis of aflatoxin.Plant-derived natural compounds are superior to synthetic fungicide in inhibiting the growth of A.flavus benefiting from their high safety to the environment,humans and stock,and low cost.This study aimed to evaluate the antifungal effects and potential antifungal mechanisms of three plant-derived compounds(octanal,nonanal and decanal)against A.flavus.We determined the minimum inhibitory concentrations(MICs)and action mechanism of the three volatile aldehydes on A.flavus and also performed calcofluor white(CW)staining for visualizing the distribution of septa.Cell respiration metabolism and the pathogenicity on maize kernels were also carried out to evaluate the efficacy of the three volatile aldehydes on the growth of A.flavus.The results showed that the three volatile aldehydes could inhibit the germination of spores and mycelial growth of A.flavus,the MICs on spores and mycelia were:octanal(1.0 and 0.5μL/mL),nonanal(0.5 and 2.0μL/mL),and decanal(1 and 5μL/mL).The three volatile aldehydes could strongly damage the integrity of both the cell wall and the cell membrane of A.flavus.Meanwhile,they could decrease the content of total lipid and inhibit respiration metabolism of A.flavus cell.Results of in vitro antifungal test showed that all the three volatile aldehydes could effectively prevent the growth of A.flavus on maize kernels.The study revealed that octanal,nonanal and decanal could effectively inhibit the growth of A.flavus both in culture medium and on maize kernels to different extent.The results confirmed that the plant-derived compounds could be developed into promising antifungal agents applied in the preservation of grains.This study provides a theoretical basis for the research and application of potential antifungal agents.展开更多
We studied the relationship between sclerotia formation and aflatoxin production by Aspergillusflavus strains isolated from maize kernels from Nandi County. Isolates recovered from maize kernels were tested for their ...We studied the relationship between sclerotia formation and aflatoxin production by Aspergillusflavus strains isolated from maize kernels from Nandi County. Isolates recovered from maize kernels were tested for their ability to form sclerotia on different growth media. PCR analysis was done on the isolates to detect 2 structural genes, aflD and aflQ, involved in aflatoxin biosynthesis pathway. Positive A. flavus isolates for one or both genes were grown on Yeast Extract Sucrose Agar medium and aflatoxins quantified using LCMSMS. All the isolates formed large sclerotia and their formation was influenced by media type but could not be related to amount of aflatoxins produced both in vivo and in vitro. Though sclerotia are perennating structures and so contribute to survival index of a fungus, their initiation is regulated by external factors though ability to form is genetic. This brings ambiguity of their presence or abundance as a measure of toxicity.展开更多
A new oxygenated tricyclic cyclopiazonic acid(CPA)alkaloid,asperorydine Q(1),along with seven known compounds,namely,asperorydines O(2)and J(3),speradine H(4),cyclopiamides A(5)and H(6),saadamysin(7),and pyrazinemetha...A new oxygenated tricyclic cyclopiazonic acid(CPA)alkaloid,asperorydine Q(1),along with seven known compounds,namely,asperorydines O(2)and J(3),speradine H(4),cyclopiamides A(5)and H(6),saadamysin(7),and pyrazinemethanol(8),were isolated from the coral-associated Aspergillus flavus GXIMD 02503.The structures were elucidated by physicochemical properties and comprehensive spectroscopic data analysis.Compounds 1−5 and 7−8 exhibited potent inhibition of lipopolysaccharide(LPS)-induced nuclear factor-κB(NF-κB)with the IC50 values ranging from 6.5 to 21.8μmol L^(−1).In addition,the most potent one,pyrazinemethanol(8),dose-dependently suppressed receptor activator of NF-κB ligand(RANKL)-induced osteoclast differentiation without obvious cytotoxicity in bone marrow macrophages cells(BMMCs),suggesting it is a promising lead compound for the treatment of osteolytic diseases.展开更多
Anthraquinone dyes are a class of typical carcinogenic and hard-biodegradable organic pollutants.This study aimed to enhance the decolorization of anthraquinone dye by rationally designing an expected immobilized syst...Anthraquinone dyes are a class of typical carcinogenic and hard-biodegradable organic pollutants.This study aimed to enhance the decolorization of anthraquinone dye by rationally designing an expected immobilized system.Reactive blue 4(RB4) was used as a substrate model and a previous isolated dyedegrading strain Aspergillus flavus A5pl was purposefully immobilized.Considering the effects of cell attachment and mass transfer,the polyurethane foam(PUF) with open pore structure was selected as the immobilization carrier.Results showed that the RB4 decolorization efficiency was significant enhanced after immobilization.Compared to the free mycelium system,the decolorization time of200 mg·L^(-1)RB4 was shortened from 48 h to 28 h by the PUF-immobilized cell system.Moreover,the PUF-immobilized system could tolerate RB4 up to 2000 mg-L^(-1).In the packed bed bioreactor(PBBR),an average decolorization efficiency of 93.3% could be maintained by the PUF-immobilized system for26 days.The decolorization process of RB4 was well described by the logistic equation and the degradation pathway was discussed.It was found that the higher specific growth rate of the PUF-immobilized cells was one of reasons for the enhanced decolorization.The good performance of the PUFimmobilized cell system would make it have potential application value for RB4 bioremediation.展开更多
The inhibitory effeet of crude extracts of garlic, clove and carrot at concentrations of 20,000, 40,000,60,000, 80,000 and 100,000 μg/mL on growth of Aspergillus and aflatoxin production in rice was investigated. The...The inhibitory effeet of crude extracts of garlic, clove and carrot at concentrations of 20,000, 40,000,60,000, 80,000 and 100,000 μg/mL on growth of Aspergillus and aflatoxin production in rice was investigated. Theresults showed that garlic, clove and carro could inhibit the growth of A. jlavus and aflatoxin production. Garlic and cloveat 100,000 μg/mL. highly reduced the level of anatoxin from 5.94 to 0. 15 and 0.06 μg/g respectively whereas carrot at20,000μg/mL reduced the most level of aflatoxin from 5.94 to 0.03μg/g. Garlic, clove and carrot at 100,000μg/mL also inhibited the mould groWth. The most effective herb for inhibiting the growth of A. flavus and anatoxin production was garlic.展开更多
Aflatoxin, the secondary metabolite of Aspergillus flavus and A. parasiticus, is the most toxic product in nature. In this study, N-acetylcysteine (NAC), ascorbate, and H2O2 were used to ascertain their effects on f...Aflatoxin, the secondary metabolite of Aspergillus flavus and A. parasiticus, is the most toxic product in nature. In this study, N-acetylcysteine (NAC), ascorbate, and H2O2 were used to ascertain their effects on fungal metabolic response of A. flavus. The results demonstrated that NAC did not affect fungal growth, but inhibited the aflatoxin Bt production, with the concomitant sporulation reduction. NAC increased the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG), but decreased the activity of glutathione reductase (GR). Ascorbate had similar effect on fungal growth, sporulation, and GR activity, but GSH/GSSG and total glutathione (tGSH, including GSH and GSSG) were significantly increased. H2O2 at high concentration (5 mM) inhibited fungal growth, but the aflatoxin production was increased. At the same time, it reduced GR activity and enhanced tGSH. Though reductive agents had different effects on GSH metabolism, reductive conditions inhibited aflatoxin production and sporulation without any effect on fungal growth. The results in this report confirmed that the relationship between oxidative stress and aflatoxin production is theoretically important in controlling aflatoxin contamination.展开更多
In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus,we screened out 17sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs....In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus,we screened out 17sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs.The size of SRAP fragments ranged from 120 to 2100 bp.Primer pair Me10/Em9 produced the maximum number of polymorphic bands(12 bands),while Me8/Em13 produced the fewest number of polymorphic bands(only 1).Through analysis genetic diversity ability of different sets of primer pairs,the set of 12 primer pairs was selected for SRAP genetic marker of A.flavus.Cluster analysis was performed based on the genetic similarity coefficients,which ranged from 0.53 to 0.89.A dendrogram assembled using the unweighted pair-group method with arithmetic averages grouped A.flavus samples into 5 main clusters.The results suggested that SRAP marker is a useful molecular technology for the diversity of A.flavus from peanut soils in China.展开更多
Aflatoxin contamination of peanuts is one of the most concerns in peanut production in China.Applying nonaflatoxigenic Aspergillus flavus strains,based on competitive exclusion,has been proved to be a promising strate...Aflatoxin contamination of peanuts is one of the most concerns in peanut production in China.Applying nonaflatoxigenic Aspergillus flavus strains,based on competitive exclusion,has been proved to be a promising strategy to reduce aflatoxin contamination in pre-harvest peanuts.Two non-aflatoxigenic A.flavus strains collected in China,which have been proved effectively reducing aflatoxin in the laboratory,were mixed with high aflatoxin producer to the soil in peanut growing season.The two non-aflatoxigenic strains significantly(P<0.05)reduced aflatoxin contamination in peanut kernels under both normal and drought stresses in two fields.Compared to control,the total aflatoxin(sum of aflatoxin B1 and B2)was reduced 26.7–99.12%in field 1,and 84.96–99.33%in field 2.The aflatoxin was reduced 84.96–99.33%under drought stress in two fields.The present study indicated the non-aflatoxigenic A.flavus strains could be potential biocontrol agents for reducing aflatoxin contamination under field condition.展开更多
Infections caused by opportunistic organisms which have been known asetiologic agents of disease become more and more frequent. Aspergillus spp. is one of the agents.Fungi of aspergillus genus are widely distributed i...Infections caused by opportunistic organisms which have been known asetiologic agents of disease become more and more frequent. Aspergillus spp. is one of the agents.Fungi of aspergillus genus are widely distributed in nature, particularly in the soil and in thedecomposed vegetation. They are frequent opportunist pathogens in immunocompromised patients. Themost frequent causative organisms that cause cutaneous aspergillosis are A. fumigatus and A. flavus.In this report, we present a case of primary cutaneous aspergillosis manifested by ulceration ofthe shank due to A. flavus. The patient had no deficiency of immunological status and severe diseaseassociated with fungal infection. Excellent response was shown to anti-fungal therapy.展开更多
Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi ...Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillusflavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A.flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water.展开更多
The contamination of Aspergillus flavus and subsequent aflatoxins(AFs)has been considered as one of the most serious food safety problems due to their acute and chronic adverse effects on humans and animals.This revie...The contamination of Aspergillus flavus and subsequent aflatoxins(AFs)has been considered as one of the most serious food safety problems due to their acute and chronic adverse effects on humans and animals.This review collects the available information from recent years on the effect of the major environmental factors such as water activity(a_(w)),temperature,CO_(2),and pH on the fungal growth,the expression of AFs-related genes,and AFs production by A.flavus on foods.In particular,the relationship between the relative expression of key regulatory(aflR and aflS)and structural genes(aflD,aflO,aflQ,etc.)and AFs production under different environmental conditions are collected and discussed.The information collected in this review can be used to design control strategies of A.flavus and AFs contamination in practical applications,primarily during storage and processing.These data suggest that integrating various post-harvest methods with synergistic functions may be more efficient for the control of A.flavus growth and AFs production,although the individual environmental factors alone have an impact.展开更多
Determination of volatile organic components(VOC)produced in high acid upland rice vinegar was conducted using GC-MS.Acetic acid and ethyl acetate at 9.11%and 2.69%(v/v),respectively,were major VOC found in the vinega...Determination of volatile organic components(VOC)produced in high acid upland rice vinegar was conducted using GC-MS.Acetic acid and ethyl acetate at 9.11%and 2.69%(v/v),respectively,were major VOC found in the vinegar while the others were isobutyl acetate,isobutyl alcohol,isoamyl acetate,isoamyl alcohol,phenethyl acetate and phenethyl alcohol.Subsequently,vinegar and VOC were tested,in vitro,for their inhibition on conidia germination of 10^(3) conidia/mL of Aspergillus flavus.The exposure with 10%(v/v)of vapor-phase vinegar and pure acetic acid completely inhibited the germination of conidia with 30 min exposure,while VOC mixture of 9.11%(v/v)acetic acid,0.08%(v/v)isoamyl alcohol,0.45%(v/v)phenethyl alcohol and 0.01%(v/v)isobutyl alcohol with 45 min exposure could achieve the same target.Then,vinegar vapor was tested on the inhibition of conidia germination and aflatoxin production of A.flavus during 90 d subsequent storage of dried chili pepper.Complete inhibition of conidia germination and aflatoxin production were achieved with the 40 min exposure of 1.04±0.03 mmol/L of vaporized vinegar.Our results showed that fumigation of upland rice vinegar containing antifungal VOC is a simple and an economical method for commercial preservation of dried chili pepper.Upland rice vinegar is a novel bio-fumigant for prevention of mycotoxin production in dried food and feed products during storage.展开更多
The incidence of CIED(Cardiac Implantable Electronic Devices)infections is 0.13%–8.0%.[1,2]Fungal organisms account for up to 10%and Aspergillus infections are extremely rare.Here,we present a case of CIED-related As...The incidence of CIED(Cardiac Implantable Electronic Devices)infections is 0.13%–8.0%.[1,2]Fungal organisms account for up to 10%and Aspergillus infections are extremely rare.Here,we present a case of CIED-related Aspergillus infection in an immunocompetent patient.展开更多
The microbial agent ARC-BBBE demonstration trials were conducted in four provinces in the main peanutproducing areas of the Huang-huai-hai plain of China.The results revealed that the application of ARC-BBBE led to a ...The microbial agent ARC-BBBE demonstration trials were conducted in four provinces in the main peanutproducing areas of the Huang-huai-hai plain of China.The results revealed that the application of ARC-BBBE led to a 1.09–1.70 fold increase in the number of nodules in the treatment group at the demonstration site compared to the control group.Moreover,the nodule weight in the treatment group was 0.80–3.32 times higher than that of the control group,and nitrogenase activity per plant showed a significant enhancement by 1.00–2.83 fold compared to controls.Additionally,notable improvements were observed in terms of increased fresh weight of whole plants,well-filled pod numbers,and enhanced growth performance;ultimately resulting in a harvest yield increase ranging from 9.46%to 49.04%.The abundance of Aspergillus flavus in rhizosphere soil was determined by the dilution spread plate method,and the inhibition rate was up to 86.7%.The application of ARC-BBBE in the significant peanut-producing areas of Huang-huai-hai has effects of promoting growth,nodulation,and increasing production.At the same time,it has the effect of inhibiting and controlling soil Aspergillus flavus,which provides a new green and low-carbon way to promote the high-quality development of the peanut industry.展开更多
基金the National Key R&D Program of China(2022YFF1100702)Major project of Hubei Hongshan Laboratory(2021hszd015),National Natural Sciences Foundation of China(32030085,U22A20551)+1 种基金Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAASASTIP-2021-OCRI)Knowledge Innovation Program of Wuhan-Shuguang Project(3570).
文摘In order to grasp the distribution of Aspergillus flavus in the soil of peanut production areas in China,A.flavus biomarkers were tested on 555 soil samples from 37 sampling points in 17 provinces,peanut fields in four agroecological zones(Southern area,Yangtze River Basin,Northern area,Northeast area).The results showed that(1)the cultivation amount of A.flavus per gram of soil in the Yangtze River Basin is 1.30 times that of the southern area,1.56 times that of the northern area,and 6.20 times that of the northeast area,with obvious regional characteristics.(2)In the Yangtze River basin,the change of longitude in the east-west direction has no direct impact on the cultivation amount of A.flavus per gram of soil.(3)In the east coast,the A.flavus cultivated per gram of soil increased first and then decreased with the increase of latitude from south to north.(4)A.flavus can be isolated in the soil samples above 1000 m.Field pollution is an important source of aflatoxin contamination in peanut.The study on the distribution of A.flavus in soil in China could provide theoretical support for the early warning and prevention and control measures of aflatoxin contamination in peanut.
基金supported by the National Natural Science Foundation of China (30771353)the Natural Science Foundation of Jiangsu Province, China(BK2007078)the Open Subject of Key Laboratory of Plant Functional Genomics,Ministry of Education of China (K06003)
文摘Maize (Zea mays L.), one of main crops in the world, is easily susceptible to Aspergillusflavus (Link: fr) infection, resulting huge loses worldwide. Breeding for A. flavus resistance has been proved an efficient way to solve the problem of aflatoxin contamination. Genetic analysis of the sources of resistance to A.flavus in maize is necessary for this purpose. The complete diallel crosses of 6 inbred lines with different resistance to A.flavus infection were implemented. Inoculation categorical data of each cross were analyzed with the additive-dominant and additive-dominant-epitasis genetic models. Results indicated some crosses fitted the 2 major genes with additive-dominant-epitasis genetic model. Others fitted the major gene and polygene mixed model. Moreover, the additive, dominant, and epitasis effects varied in crosses. The A.flavus resistance was controlled by both major gene and polygene.
基金the financial support of the Doctor Research Fund of Henan University of Technology(2019BS019)the Natural Science Research Projects of Education Department of Henan Province(21A550005)the Innovative Funds plan of Henan University of Technology(2020ZKCJ17)。
文摘To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-methoxybenzaldehyde)and the possible antifungal mechanisms have been investigated.All the four volatile aldehydes could inhibit the germination of spores,and the minimum inhibitory concentrations(MICs)of them were in this order:vanillin(200μg/mL),o-vanillin(100μg/mL),2-hydroxy-5-methoxybenzaldehyde(100μg/mL),HMB(70μg/mL).The minimum fungicidal concentrations(MFCs)of them were in this order:vanillin(240μg/mL),o-vanillin(160μg/mL),HMB(140μg/mL),2-hydroxy-5-methoxybenzaldehyde(140μg/mL).Spore size was arrested at 0 h with the treatment of the four volatile aldehydes.Effects of the four volatile aldehydes on the cell wall and cell membrane integrity of A flavus were observed by calcofluor white(CW)staining and propidium iodide(PI)staining.The results showed that HMB exerted the strongest antifungal and fungicidal effects on the growth of A.flavus.The four volatile aldehydes had little influence on cell wall integrity after 3-hour treatment,however,they could strongly damage the cell membrane integrity.All the four volatile aldehydes could effectively prevent the growth of A.flavus on peanut seeds.The antifungal mechanisms of the four volatile aldehydes provide theoretical foundations for their development of new antifungal agents.
基金supported by the Key Lab of Biomass and Energy of Anhui Educational Department of China
文摘In the process of the fermentation of steroid C11α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy ion beam implantation is a new tool for breeding excellent mutant strains. In this study, the ion beam implantation experiments were performed by infusing two different ions: argon ion (Ar^+) and nitrogen ion (N^+). The results showed that the optimal ion implantation was N^+ with an optimum dose of 2.08- 1015 ions/cm^2, with which the mutant strain AF-ANm16 that produced no red pigment was obtained. The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation, which could be utilized in industrial fermentation. The differences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA (RAPD). The results indicated that the frequency of variation was 7.00%, which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation.
基金This study was funded by the Doctor Research Fund of Henan University of Technology(grant number 2019BS019)the Natural Science Research Projects of Education Department of Henan Province(21A550005).
文摘The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis of aflatoxin.Plant-derived natural compounds are superior to synthetic fungicide in inhibiting the growth of A.flavus benefiting from their high safety to the environment,humans and stock,and low cost.This study aimed to evaluate the antifungal effects and potential antifungal mechanisms of three plant-derived compounds(octanal,nonanal and decanal)against A.flavus.We determined the minimum inhibitory concentrations(MICs)and action mechanism of the three volatile aldehydes on A.flavus and also performed calcofluor white(CW)staining for visualizing the distribution of septa.Cell respiration metabolism and the pathogenicity on maize kernels were also carried out to evaluate the efficacy of the three volatile aldehydes on the growth of A.flavus.The results showed that the three volatile aldehydes could inhibit the germination of spores and mycelial growth of A.flavus,the MICs on spores and mycelia were:octanal(1.0 and 0.5μL/mL),nonanal(0.5 and 2.0μL/mL),and decanal(1 and 5μL/mL).The three volatile aldehydes could strongly damage the integrity of both the cell wall and the cell membrane of A.flavus.Meanwhile,they could decrease the content of total lipid and inhibit respiration metabolism of A.flavus cell.Results of in vitro antifungal test showed that all the three volatile aldehydes could effectively prevent the growth of A.flavus on maize kernels.The study revealed that octanal,nonanal and decanal could effectively inhibit the growth of A.flavus both in culture medium and on maize kernels to different extent.The results confirmed that the plant-derived compounds could be developed into promising antifungal agents applied in the preservation of grains.This study provides a theoretical basis for the research and application of potential antifungal agents.
文摘We studied the relationship between sclerotia formation and aflatoxin production by Aspergillusflavus strains isolated from maize kernels from Nandi County. Isolates recovered from maize kernels were tested for their ability to form sclerotia on different growth media. PCR analysis was done on the isolates to detect 2 structural genes, aflD and aflQ, involved in aflatoxin biosynthesis pathway. Positive A. flavus isolates for one or both genes were grown on Yeast Extract Sucrose Agar medium and aflatoxins quantified using LCMSMS. All the isolates formed large sclerotia and their formation was influenced by media type but could not be related to amount of aflatoxins produced both in vivo and in vitro. Though sclerotia are perennating structures and so contribute to survival index of a fungus, their initiation is regulated by external factors though ability to form is genetic. This brings ambiguity of their presence or abundance as a measure of toxicity.
基金supported by the Natural Science Foundation of Guangxi(No.2020GXNSFGA297002)the Specific Research Project of Guangxi for Research Bases and Talents(No.AD20297003)+3 种基金the Special Fund for Bagui Scholars of Guangxi(Y.Liu)the National Natural Science Foundation of China(Nos.U20A20101,22007019)the Key State Laboratory Talent Project of Guangxi Normal University(No.CMEMR 2019-A05)the Open Project of CAS Key Laboratory of Tropical Marine Bioresources and Ecology(No.LMB20211005).
文摘A new oxygenated tricyclic cyclopiazonic acid(CPA)alkaloid,asperorydine Q(1),along with seven known compounds,namely,asperorydines O(2)and J(3),speradine H(4),cyclopiamides A(5)and H(6),saadamysin(7),and pyrazinemethanol(8),were isolated from the coral-associated Aspergillus flavus GXIMD 02503.The structures were elucidated by physicochemical properties and comprehensive spectroscopic data analysis.Compounds 1−5 and 7−8 exhibited potent inhibition of lipopolysaccharide(LPS)-induced nuclear factor-κB(NF-κB)with the IC50 values ranging from 6.5 to 21.8μmol L^(−1).In addition,the most potent one,pyrazinemethanol(8),dose-dependently suppressed receptor activator of NF-κB ligand(RANKL)-induced osteoclast differentiation without obvious cytotoxicity in bone marrow macrophages cells(BMMCs),suggesting it is a promising lead compound for the treatment of osteolytic diseases.
基金funded by the National Natural Science Foundation of China(21066001)the Scientific Research Foundation of Guangxi University(XJZ130360)the Innovation and Entrepreneurship Training Program for Undergraduate of Guangxi University(202010593174)。
文摘Anthraquinone dyes are a class of typical carcinogenic and hard-biodegradable organic pollutants.This study aimed to enhance the decolorization of anthraquinone dye by rationally designing an expected immobilized system.Reactive blue 4(RB4) was used as a substrate model and a previous isolated dyedegrading strain Aspergillus flavus A5pl was purposefully immobilized.Considering the effects of cell attachment and mass transfer,the polyurethane foam(PUF) with open pore structure was selected as the immobilization carrier.Results showed that the RB4 decolorization efficiency was significant enhanced after immobilization.Compared to the free mycelium system,the decolorization time of200 mg·L^(-1)RB4 was shortened from 48 h to 28 h by the PUF-immobilized cell system.Moreover,the PUF-immobilized system could tolerate RB4 up to 2000 mg-L^(-1).In the packed bed bioreactor(PBBR),an average decolorization efficiency of 93.3% could be maintained by the PUF-immobilized system for26 days.The decolorization process of RB4 was well described by the logistic equation and the degradation pathway was discussed.It was found that the higher specific growth rate of the PUF-immobilized cells was one of reasons for the enhanced decolorization.The good performance of the PUFimmobilized cell system would make it have potential application value for RB4 bioremediation.
文摘The inhibitory effeet of crude extracts of garlic, clove and carrot at concentrations of 20,000, 40,000,60,000, 80,000 and 100,000 μg/mL on growth of Aspergillus and aflatoxin production in rice was investigated. Theresults showed that garlic, clove and carro could inhibit the growth of A. jlavus and aflatoxin production. Garlic and cloveat 100,000 μg/mL. highly reduced the level of anatoxin from 5.94 to 0. 15 and 0.06 μg/g respectively whereas carrot at20,000μg/mL reduced the most level of aflatoxin from 5.94 to 0.03μg/g. Garlic, clove and carrot at 100,000μg/mL also inhibited the mould groWth. The most effective herb for inhibiting the growth of A. flavus and anatoxin production was garlic.
基金the National Natural Science Foundation of China(30600408)Natural Science Foundation of Hubei Province,China(2006ABA360).
文摘Aflatoxin, the secondary metabolite of Aspergillus flavus and A. parasiticus, is the most toxic product in nature. In this study, N-acetylcysteine (NAC), ascorbate, and H2O2 were used to ascertain their effects on fungal metabolic response of A. flavus. The results demonstrated that NAC did not affect fungal growth, but inhibited the aflatoxin Bt production, with the concomitant sporulation reduction. NAC increased the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG), but decreased the activity of glutathione reductase (GR). Ascorbate had similar effect on fungal growth, sporulation, and GR activity, but GSH/GSSG and total glutathione (tGSH, including GSH and GSSG) were significantly increased. H2O2 at high concentration (5 mM) inhibited fungal growth, but the aflatoxin production was increased. At the same time, it reduced GR activity and enhanced tGSH. Though reductive agents had different effects on GSH metabolism, reductive conditions inhibited aflatoxin production and sporulation without any effect on fungal growth. The results in this report confirmed that the relationship between oxidative stress and aflatoxin production is theoretically important in controlling aflatoxin contamination.
基金the grants from the Natural Science Foundation of Shandong Province(ZR2020MC103,ZR2021MC040)Innovation Project of Agricultural Science and Technology of Shandong Academy of Agricultural Sciences(CXGC2022B06,CXGC2022F33)。
文摘In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus,we screened out 17sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs.The size of SRAP fragments ranged from 120 to 2100 bp.Primer pair Me10/Em9 produced the maximum number of polymorphic bands(12 bands),while Me8/Em13 produced the fewest number of polymorphic bands(only 1).Through analysis genetic diversity ability of different sets of primer pairs,the set of 12 primer pairs was selected for SRAP genetic marker of A.flavus.Cluster analysis was performed based on the genetic similarity coefficients,which ranged from 0.53 to 0.89.A dendrogram assembled using the unweighted pair-group method with arithmetic averages grouped A.flavus samples into 5 main clusters.The results suggested that SRAP marker is a useful molecular technology for the diversity of A.flavus from peanut soils in China.
基金This research was supported by the Central Public-interest Scientific Institution Basal Research Fund(2021-2060302-061-019)the National Natural Science Foundation of China(Grant Nos.32001510 and 31461143022)+1 种基金China Agricultural Research System(CARS-13)the Innovation Program of the Chinese Academy of Agricultural Sciences(2021-2060302-049-031).
文摘Aflatoxin contamination of peanuts is one of the most concerns in peanut production in China.Applying nonaflatoxigenic Aspergillus flavus strains,based on competitive exclusion,has been proved to be a promising strategy to reduce aflatoxin contamination in pre-harvest peanuts.Two non-aflatoxigenic A.flavus strains collected in China,which have been proved effectively reducing aflatoxin in the laboratory,were mixed with high aflatoxin producer to the soil in peanut growing season.The two non-aflatoxigenic strains significantly(P<0.05)reduced aflatoxin contamination in peanut kernels under both normal and drought stresses in two fields.Compared to control,the total aflatoxin(sum of aflatoxin B1 and B2)was reduced 26.7–99.12%in field 1,and 84.96–99.33%in field 2.The aflatoxin was reduced 84.96–99.33%under drought stress in two fields.The present study indicated the non-aflatoxigenic A.flavus strains could be potential biocontrol agents for reducing aflatoxin contamination under field condition.
文摘Infections caused by opportunistic organisms which have been known asetiologic agents of disease become more and more frequent. Aspergillus spp. is one of the agents.Fungi of aspergillus genus are widely distributed in nature, particularly in the soil and in thedecomposed vegetation. They are frequent opportunist pathogens in immunocompromised patients. Themost frequent causative organisms that cause cutaneous aspergillosis are A. fumigatus and A. flavus.In this report, we present a case of primary cutaneous aspergillosis manifested by ulceration ofthe shank due to A. flavus. The patient had no deficiency of immunological status and severe diseaseassociated with fungal infection. Excellent response was shown to anti-fungal therapy.
基金supported by the National High-Tech Research and Development Program (863) of China (No. 2012AA062607)the National Natural Scientific Foundation of China (No. 51278482, 51108440)the 100 Talents Program of Chinese Academy of Sciences
文摘Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillusflavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A.flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water.
基金We gratefully acknowledge the financial support of National Key R&D Program of China(2016YFD0400105).
文摘The contamination of Aspergillus flavus and subsequent aflatoxins(AFs)has been considered as one of the most serious food safety problems due to their acute and chronic adverse effects on humans and animals.This review collects the available information from recent years on the effect of the major environmental factors such as water activity(a_(w)),temperature,CO_(2),and pH on the fungal growth,the expression of AFs-related genes,and AFs production by A.flavus on foods.In particular,the relationship between the relative expression of key regulatory(aflR and aflS)and structural genes(aflD,aflO,aflQ,etc.)and AFs production under different environmental conditions are collected and discussed.The information collected in this review can be used to design control strategies of A.flavus and AFs contamination in practical applications,primarily during storage and processing.These data suggest that integrating various post-harvest methods with synergistic functions may be more efficient for the control of A.flavus growth and AFs production,although the individual environmental factors alone have an impact.
基金The authors would like to give our deep appreciation to the King Mongkut’s Institute of Technology Ladkrabang Research Fund(KREF116101),Thailand,for the financial support of the study.In addition,the authors are especially grateful to Professor Anthony Keith Thompson,a visiting professor at School of Food Industry,King Mongkut’s Institute of Technology Ladkrabang,formally Professor at Cranfield University,UK for his valuable comment and edit the manuscript.
文摘Determination of volatile organic components(VOC)produced in high acid upland rice vinegar was conducted using GC-MS.Acetic acid and ethyl acetate at 9.11%and 2.69%(v/v),respectively,were major VOC found in the vinegar while the others were isobutyl acetate,isobutyl alcohol,isoamyl acetate,isoamyl alcohol,phenethyl acetate and phenethyl alcohol.Subsequently,vinegar and VOC were tested,in vitro,for their inhibition on conidia germination of 10^(3) conidia/mL of Aspergillus flavus.The exposure with 10%(v/v)of vapor-phase vinegar and pure acetic acid completely inhibited the germination of conidia with 30 min exposure,while VOC mixture of 9.11%(v/v)acetic acid,0.08%(v/v)isoamyl alcohol,0.45%(v/v)phenethyl alcohol and 0.01%(v/v)isobutyl alcohol with 45 min exposure could achieve the same target.Then,vinegar vapor was tested on the inhibition of conidia germination and aflatoxin production of A.flavus during 90 d subsequent storage of dried chili pepper.Complete inhibition of conidia germination and aflatoxin production were achieved with the 40 min exposure of 1.04±0.03 mmol/L of vaporized vinegar.Our results showed that fumigation of upland rice vinegar containing antifungal VOC is a simple and an economical method for commercial preservation of dried chili pepper.Upland rice vinegar is a novel bio-fumigant for prevention of mycotoxin production in dried food and feed products during storage.
基金supported by National Natural Science Foundation of China(No.81600267) to HAN ZL
文摘The incidence of CIED(Cardiac Implantable Electronic Devices)infections is 0.13%–8.0%.[1,2]Fungal organisms account for up to 10%and Aspergillus infections are extremely rare.Here,we present a case of CIED-related Aspergillus infection in an immunocompetent patient.
基金The authors thank the National Natural Sciences Foundation of China(32030085,U22A20551)Major project of Hubei Hongshan Laboratory(2021hszd015)+1 种基金Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP2021-OCRI)Knowledge Innovation Program of Wuhan-Shuguang Project(3570).
文摘The microbial agent ARC-BBBE demonstration trials were conducted in four provinces in the main peanutproducing areas of the Huang-huai-hai plain of China.The results revealed that the application of ARC-BBBE led to a 1.09–1.70 fold increase in the number of nodules in the treatment group at the demonstration site compared to the control group.Moreover,the nodule weight in the treatment group was 0.80–3.32 times higher than that of the control group,and nitrogenase activity per plant showed a significant enhancement by 1.00–2.83 fold compared to controls.Additionally,notable improvements were observed in terms of increased fresh weight of whole plants,well-filled pod numbers,and enhanced growth performance;ultimately resulting in a harvest yield increase ranging from 9.46%to 49.04%.The abundance of Aspergillus flavus in rhizosphere soil was determined by the dilution spread plate method,and the inhibition rate was up to 86.7%.The application of ARC-BBBE in the significant peanut-producing areas of Huang-huai-hai has effects of promoting growth,nodulation,and increasing production.At the same time,it has the effect of inhibiting and controlling soil Aspergillus flavus,which provides a new green and low-carbon way to promote the high-quality development of the peanut industry.