温度和pH对不同镰刀菌生长及产毒的影响

以从小麦、玉米、大米、大麦等作物中分离得到的12株不同种类的镰刀菌菌株为研究对象,探究不同温度和p H对其生长及产毒的影响。结果表明,镰刀菌在10~35℃和p H3~11范围内均能够生长,最适温度为20~30℃,最适p H为6~8。供试镰刀菌能够产生的毒素主要为A型单端孢霉烯族毒素、B型单端孢霉烯族毒素、伏马毒素和镰刀菌酸,产毒温度为5~40℃,但不同菌株的最适产毒温度存在差异;产毒过程受p H影响较大,过酸(p H3~5)及过碱(p H9~11)的条件下均未检测到任何毒素。总体上看,不同种类镰刀菌产毒类型存在差异,毒素产量受温度和p H影响比生长更大,且大多数菌株的生长与产毒最适条件并不一致。     

玉米赤霉烯酮毒性研究进展(综述)

玉米赤霉烯酮 (Ｚｅａｒａｌｅｎｏｎｅ ,ＺＥＡ) ,又称Ｆ - 2毒素 ,是由镰刀菌产生的一种霉菌毒素。主要产毒菌株为禾谷镰刀菌 ,此外 ,粉红镰刀菌、尖孢镰刀菌、三线镰刀菌、串珠镰刀菌、黄色镰刀菌以及雪腐镰刀菌等也能产生ＺＥＡ。玉米、小麦、燕麦和大麦等作物易受到ＺＥＡ     

小麦产毒病原菌及其毒素防控的研究进展

小麦是全球第二大粮食作物,每年因病害造成小麦严重减产,品质下降。一些病原菌还能够产生真菌毒素,进一步危害小麦及其制品的质量安全,对人畜健康造成巨大危害。由镰刀菌引起的小麦赤霉病是我国最主要的小麦病害之一,由交链孢引起的小麦黑胚病也备受关注。这2种真菌既能引起小麦病害,又能产生真菌毒素,故称之为产毒病害。镰刀菌产生的脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)、玉米赤霉烯酮(zearalenone,ZEN)、伏马菌素等和交链孢产生的交链孢酚(alternariol,AOH)、交链孢酚单甲醚(alternariol monomethyl ether,AME)和细交链格孢酮酸(tenuazonic acid,Te A)等是2类病原菌产生的主要真菌毒素。本文综述了能引起小麦产毒病害的镰刀菌和交链孢的特点、真菌毒素以及病害和毒素的防控技术,尤其是2类病原菌引起的小麦病害和真菌毒素的防控。这将为后期防治小麦产毒病害及控制毒素产生的研究提供有利参考。     

基于PCR技术的产真菌毒素镰刀菌分子诊断研究进展

镰刀菌属于自然界中最频繁产生毒素的真菌类别之一。该属真菌的毒素类次生代谢产物主要包括单端孢霉烯族化合物、伏马菌素和玉米赤霉烯酮3类,引起人畜各种生理异常甚至癌变。本文综述了3类镰刀菌毒素的结构和危害、生物合成的分子机理以及聚合酶链式反应(polymerase chain reaction,PCR)技术在其产生菌分子检测中的应用进展,突出了产毒真菌快速分子诊断技术在毒素早期预警、危害前置化干预中的意义。同时,在剖析现有产毒真菌PCR检测体系可能存在问题的基础上,提出克服瓶颈方法和进一步提高体系可靠性的有效策略。     

赤霉病麦中禾谷镰刀菌产毒性能的观察

禾谷镰刀菌是麦类、玉米等主要农作物和某些植物的病原菌。由于本菌的危害,不但能造成粮食严重减产,其产生的有毒代谢产物——霉菌毒素(主要是呕吐毒素,简称DON)还可对粮食造成污染。人及家畜摄食带毒的粮食,往往发生食物中毒。本研究的目的是了解我国禾谷镰刀菌的产毒情况,以及筛选高产毒菌株应用于毒素的制备,以便进一步开展呕吐毒素的毒性研究工作,并为     

粮食中新兴真菌毒素的污染现状及毒理学研究进展

产毒真菌污染粮食等农产品产生有毒有害的次级代谢产物,称真菌毒素,严重威胁食用和饲用产品的质量安全。较为常见的真菌毒素包括黄曲霉毒素、镰刀菌毒素脱氧雪腐镰刀烯醇、玉米赤霉烯酮等,国内外针对这些主要污染毒素制定了相应的限量标准。近年来,随着真菌毒素研究的发展和检测技术的更新,一些新型真菌毒素不断被发现。将目前尚未被列入常规风险筛查和监管、也尚无相关限量标准的真菌毒素种类,称谓新兴毒素（Emerging toxins）。目前检出频次高、污染较为严重的新兴毒素主要由镰刀菌属（Fusarium spp.）和链格孢属（Alternaria spp.）等产毒真菌产生。这些新兴真菌毒素通常与主要毒素复合污染,本文将依据现有的风险调查报告与数据,综述粮食中常见新兴镰刀菌和链格孢毒素的污染现状和毒理学研究进展,为真菌毒素的全面风险评估和管控技术研发提供依据。     

食品中白僵菌素和恩镰孢菌素的污染情况及分析方法研究进展

介绍了食品中白僵菌素(beauvericin,BEA)和包括恩镰孢菌素A(enniatin A,ENA)、恩镰孢菌素A_1(enniatin A_1,ENA_1)、恩镰孢菌素B(enniatin B,ENB)、恩镰孢菌素B_1(enniatin B_1,ENB_1)在内的4种主要的恩镰孢菌素(enniatins,ENNs)的分类、毒性和分析方法,尤其是前处理方式和各方法定量限的研究进展。综述了西班牙、摩洛哥、意大利、日本等部分国家食品中BEA和4种ENNs的污染状况以及这5种毒素与其他主要真菌毒素的协同污染情况。提出了建立针对复杂食品基质中BEA和ENNs测定的高效液相色谱-串联质谱法。     

小麦中致病真菌的分离鉴定及熏蒸对其毒力的影响

小麦受镰刀菌的感染会导致赤霉病、真菌毒素污染和减产,镰刀菌对粮食安全有着严重威胁。通过对小麦中镰刀菌株进行分离鉴定,分离出的三种菌株N1、N2、N3分别属于禾谷镰刀菌属、亚洲镰刀菌属和高秆镰刀菌属。利用产毒基因检测和真菌毒素检测对三株菌株玉米赤霉烯酮、呕吐毒素和伏马毒素的产毒情况进行分析,结果一致显示N1和N3能产生玉米赤霉烯酮和呕吐毒素,均含有PSK和Tri5两种产毒基因,而N2不产生这三种毒素。进一步通过臭氧和二氧化氯进行气体熏蒸,探究气体熏蒸对分离出的三株菌株的影响,通过观察孢子形态、菌丝体长度、菌丝形态,结果表明二氧化氯熏蒸能有效抑制菌丝生长和孢子萌发,低浓度二氧化氯（300 mg/L）处理0.5 h,可明显抑制菌丝的生长。而臭氧只能抑制孢子萌发,对菌丝的生长没有明显的抑制作用。     

2017年山东省部分地区玉米及其制品中白僵菌素和恩镰孢菌素污染调查

目的 调查山东省部分地区2017年产玉米及其制品中六酯肽类真菌毒素,包括白僵菌素(BEA)和恩镰孢菌素(ENNs)中恩镰孢菌素A(ENA)、恩镰孢菌素A₁(ENA₁)、恩镰孢菌素B(ENB)和恩镰孢菌素B₁(ENB₁)的污染情况。方法 从山东省东部、西部、南部和中部四个地区采集2017年产玉米及其制品158份,样品经乙腈-水(85∶15,V/V)提取、固相萃取柱净化后高效液相色谱-串联质谱测定5种毒素的含量。结果 BEA是158份样品中的主要污染毒素,其阳性率和平均值分别为82.3%(130/158)和65.26 μg/kg,4种ENNs的阳性率和平均值分别为ENA:55.1%(87/158)和0.28 μg/kg,ENA₁:8.2%(13/158)和0.62 μg/kg,ENB:3.8%(6/158)和1.19 μg/kg,ENB₁:56.3%(89/158)和0.13 μg/kg。玉米粒、玉米粉和玉米碴中5种毒素的平均值分别为BEA:46.96、86.45和0.17 μg/kg,ENA:0.13、0.35和0.06 μg/kg,ENA₁:0.14、0.76和0.00 μg/kg,ENB:0.23、2.15和0.00 μg/kg,ENB₁:0.21、0.15和0.08 μg/kg。东部地区样品中BEA的污染最严重,其阳性率和平均值分别为87.0%(87/100)和95.75 μg/kg;除南部地区ENA和ENB₁的阳性率较高(均为91.3%,21/23)外,4种ENNs在其他3个地区阳性率均较低,且4种ENNs在4个地区的平均值均低于BEA。结论 山东省部分地区玉米及其制品可受5种六酯肽类真菌毒素的污染,BEA的污染水平高于4种ENNs的污染水平;毒素污染存在种类和地域差异,建议在山东省开展大范围监测的基础上,重点监测东部沿海地区玉米及其制品中BEA的含量。     

谷物中DON、ZEA毒素的净化、检测、毒性与生物脱毒技术的研究

禾谷镰刀菌在侵染谷物过程中所产生的次生代谢产物——单端孢霉烯族毒素[脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)、雪腐镰刀菌烯醇(nivalenol,NIV)]以及玉米赤霉烯酮(zearalenone,ZEA)是世界上粮食安全的一个重大问题。毒素经固液萃取技术提取后,需要通过净化处理才能进行检测与分析。目前有多种净化技术用于毒素的净化,如免疫亲和柱、多功能净化柱等固相萃取柱等,以及广泛使用且简便经济的QuEChERS前处理技术。本文还介绍了禾谷镰刀菌毒素中DON、ZEA的检测方法、产毒条件、毒性以及生物脱毒技术等方面的研究进展,旨在开发与应用更安全、高效、经济的生物脱毒技术进行毒素的防御与去除,以提供安全、优质的粮食与食品。     

Effect of sourdough processing and baking on the content of enniatins and beauvericin in wheat and rye bread

The occurrence of the emerging mycotoxins enniatins (ENNs) and beauvericin (BEA) has been reported in Fusarium-infected cereals. To study the effect of sourdough processing and baking on ENN B, ENN B1, and BEA concentrations, a recently developed stable isotope dilution assay for these mycotoxins was used. After milling of wheat and rye grains naturally contaminated with ENN B and ENN B1, approximately 70–82 % of the two ENNs were found in the bran fraction and the rest remained in flour. BEA was added to flour before sourdough fermentation. In an experiment on a microscale, dough was fermented for 24 h at 30 or 40 °C, which reduced part of the ENNs and BEA in particular at 40 °C. On a standard scale, mixing, resting, and proofing of the bread dough resulted in 13–19 % reduction of the ENNs compared with flour, but in no significant change of BEA. The final baking at 200 °C for 25 min led to a further decrease of the ENNs and BEA, ranging from 9 to 28 % compared with fermented dough. In case of rye sourdough bread, greater reductions of ENNs were found in crust than in crumb. For both wheat and rye flours, overall 25–41 % of ENN B, ENN B1, and BEA were reduced during the whole sourdough bread-making process.     

Interactions between ABC‐transport proteins and the secondary Fusarium metabolites enniatin and beauvericin

Enniatins (ENN) and beauvericin (BEA) exert cytotoxic properties. Here, we observed that their impact on Ca²⁺‐homeostasis can be reversed by exogenous ATP. Thus, we investigated whether membrane‐located ATP‐binding cassette (ABC) transporters influence ENNs‐ and BEA‐induced cytotoxicity. In short‐term exposure assays breast cancer resistance protein (ABCG2)‐overexpression weakly but significantly reduced the cytotoxic activity of BEA but not ENNs. In contrast, multidrug resistance‐associated protein‐1 (ABCC1)‐ and P‐glycoprotein (ABCB1)‐overexpression was not protective under identical conditions. ABCG2‐mediated resistance against BEA was reversible by ABCG2 modulators. In long‐term exposure assays, ABCG2 and ABCB1 significantly protected against ENNs‐ and to a lesser extent BEA‐induced cytotoxicity. Moreover, both fusariotoxins potently inhibited the ABCG2‐ and ABCB1‐mediated efflux of specific fluorescent substrates, with BEA being more effective. Additionally, ATPase and photoaffinity‐labelling assays proofed interaction of both substances with ABCG2 and ABCB1. Remarkably, 2 years selection of KB‐3‐1 cells against both fusariotoxins resulted only in two‐fold ENNs but negligible BEA resistance. Interestingly, the selected sublines displayed upregulation of multidrug resistance proteins and crossresistance to other chemotherapeutics. Summarizing, ABCG2 and ABCB1 slightly but significantly protect human cells against ENNs‐ and BEA‐induced cytotoxicity. However, both mycotoxins potently interact with ABCB1 and ABCG2 transport functions suggesting influences on bioavailability of xenobiotics and pharmaceuticals.     

Occurrence of enniatins and beauvericin in 60 Chinese medicinal herbs

A total of 60 Chinese medicinal herbs were examined for contamination of the emerging Fusarium mycotoxins enniatins (ENNs) A, A1, B, B1 and beauvericin (BEA). The herbs under study are commonly used in China as both medicines and food. The dried samples of herbs were randomly collected from traditional Chinese medicine stores in Zhejiang province, China. Sample preparation was achieved by methanol extraction, followed by a simple membrane filtration step; no tedious clean-ups were involved. ENNs A, A1, B, B1 and BEA were analysed by the recently developed stable isotope dilution assays, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With limits of detection ranging between 0.8 and 1.2 µg kg^–1 for the analytes under study, 25% of all analysed samples were contaminated with at least one of the ENNs and BEA. BEA was the most frequently detected toxin with a 20% incidence in all samples. The percentages of ENN-positive samples were lower: each single ENN was detected in 6.7–11.7% of all samples. Considering the total amounts of the five mycotoxins in single samples, values between 2.5 and 751 µg kg^–1 were found. The mean total amount in positive samples was 126 µg kg^–1. Regarding ginger, the frequent occurrence of ENNs and BEA in dried ginger could be confirmed in samples from Germany. However, in fresh ginger root the toxins were not detectable. This is the first report on the presence of ENNs and BEA in Chinese medicinal herbs.     

An integrated sample preparation to determine coccidiostats and emerging Fusarium-mycotoxins in various poultry tissues with LC-MS/MS

The usefulness of an existing sample preparation technique used for ionophoric coccidiostats (lasalocid, monensin, salinomycin and narasin) was applied in the analysis of emerging Fusarium-mycotoxins beauvericin (BEA) and enniatins (ENNs) in poultry tissues (liver and meat). Also, maduramicin and liver as a new sample matrix was introduced. The developed methods were validated and applied for the determination of coccidiostats and BEA/ENNs in Finnish poultry tissues in 2004-2005. The validation parameters demonstrated that the integrated sample preparation technique is applicable to the parallel determination of these contaminants in poultry tissues. Of the samples analysed (276 meat and 43 liver), only trace levels of LAS, MON, SAL, NAR and MAD were detected in 7, 3, 5, 6 and 4% of the samples, respectively. Interestingly, for the first time, traces of BEA and ENNs could also be detected in animal tissues. BEA and ENNs A, A1, B and B1 were found in 2, 0.3, 0.6, 4 and 3% of the samples, respectively. The simultaneous presence of coccidiostats and mycotoxins was detected in three turkey samples in 2004.     

Trichothecene and beauvericin mycotoxin production and genetic variability in Fusarium poae isolated from wheat kernels from northern Italy

The importance and widespread incidence of Fusarium poae as a natural contaminant of wheat in different climatic areas warrants investigation into the genetic diversity and toxin profile of a northern Italy population. Eighty-one strains of F. poae isolated from durum wheat kernels, identified by species-specific polymerase chain reaction and translation elongation factor-1α gene sequence analysis, were genetically characterized by the amplified fragment length polymorphism (AFLP) technique and analysed by high-pressure liquid chromatography for their ability to produce the beauvericin (BEA) and trichothecene mycotoxins. A high level of variability was observed by using AFLP analyses, with the lowest level of genetic similarity among the strains being approximately 61%. Most of the strains, 95%, produced BEA at <2655 µg g^?1; 88% produced the trichothecene nivalenol at <865 µg g^?1 and 76% produced the trichothecene fusarenon-X at <167 µg g^?1. These data show that F. poae can produce high amounts of BEA together with trichothecenes, and can represent a high potential mycotoxin risk in Italy for wheat colonized by this species.     

Utility of the phylotoxigenic relationships among trichothecene-producing Fusarium species for predicting their mycotoxin-producing potential

Species of the genus Fusarium are well-known plant pathogens and mycotoxigenic fusaria are associated with health hazards to humans and animals. There is a need to understand the mechanisms of mycotoxin production by Fusarium species and to predict which produce mycotoxins. In this study, the Fusarium phylogenetic tree was first inferred among trichothecene producers and related species. We reconstructed the maximum likelihood (ML) tree based on the combined data from nucleotide sequences of rDNA cluster regions, the β-tubulin gene (β-tub) and the elongation factor 1α gene (EF-1α). Second, based on this tree topology, the ancestral states of the producing potential of type A and B trichothecenes (TriA and TriB), zearalenone (ZEN), moniliformin (MON), beauvericin (BEA) and enniatins (ENN) were reconstructed using the maximum parsimony (MP) method based on the observed production by extant species as reported in the literature. Finally, the species having the potential to produce each of these six mycotoxins was predicted on the basis of the parsimonious analysis. The ML tree indicated that the Fusarium species analysed in this study could be divided into two major clades. Clade I was divided into four distinct subclades: I-a, I-b, I-c and I-d. Furthermore, the parsimony reconstruction suggested that the potential for producing MON and ZEN was gained or lost only once, and that the producing potential for TriA and TriB, BEA and ENN was repeatedly gained and lost during the evolutionary history of the Fusarium species analysed in this study. Interestingly, the results showed the possibility that several species, about which reports were scarce with regard to mycotoxin production, have the potential to produce one or more of the six evaluated in this study. The phylogenetic information therefore helps one to predict the mycotoxin-producing potential by Fusarium species, and these “phylotoxigenic relationships” may be useful for predicting the pathogenicity of fungi.     

Epidemiology of mycotoxigenic fungi associated with Fusarium ear blight and apple blue mould: A review

Research on the epidemiology of plant diseases is briefly reviewed, focusing on two diseases caused by mycotoxin-producing pathogens: Fusarium ear (or head) blight (FEB or FHB) of small grain cereals and apple blue mould (Penicillium expansum). Pathogen development during its key life cycles is discussed in relation to important environmental factors and host resistance. Current control methods are also reviewed, focusing on cultural and biological methods. The future challenge is to understand the relationships between disease severity, fungal biomass and the production of associated mycotoxins in order to minimize risks of both disease damage to crop yields and threat to human health posed by mycotoxins.     

Relationship between Fusarium spp. diversity and mycotoxin contents of mature grains in southern Belgium

Over a 4-year period (2010–13), a survey aiming at determining the occurrence of Fusarium spp. and their relations to mycotoxins in mature grains took place in southern Belgium. The most prevalent species were F. graminearum, F. avenaceum, F. poae and F. culmorum, with large variations between years and locations. An even proportion of mating type found for F. avenaceum, F. culmorum, F. cerealis and F. tricinctum is usually a sign of ongoing sexual recombination. In contrast, an unbalanced proportion of mating type was found for F. poae and no MAT1-2 allele was present in the F. langsethiae population. Genetic chemotyping indicates a majority of deoxynivalenol (DON)-producing strains in F. culmorum (78%, all 3-ADON producers) and F. graminearum (95%, mostly 15-ADON producers), while all F. cerealis strains belong to the nivalenol (NIV) chemotype. Between 2011 and 2013, DON, NIV, enniatins (ENNs) and moniliformin (MON) were found in each field in various concentrations. By comparison, beauvericin (BEA) was scarcely detected and T-2 toxin, zearalenone and α- and β-zearalenols were never detected. Principal component analysis revealed correlations of DON with F. graminearum, ENNs and MON with F. avenaceum and NIV with F. culmorum, F. cerealis and F. poae. BEA was associated with the presence of F. tricinctum and, to a lesser extent, with the presence of F. poae. The use of genetic chemotype data revealed that DON concentrations were mostly influenced by DON-producing strains of F. graminearum and F. culmorum, whereas the concentrations of NIV were influenced by the number of NIV-producing strains of both species added to the number of F. cerealis and F. poae strains. This study emphasises the need to pay attention to less-studied Fusarium spp. for future Fusarium head blight management strategies, as they commonly co-occur in the field and are associated with a broad spectrum of mycotoxins.