小麦籽粒中原型及修饰型脱氧雪腐镰刀菌烯醇的产生规律研究

目的研究原型脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)及其修饰型的产生规律。方法以小麦籽粒为培养材料,辐照灭菌后接种禾谷镰刀菌,并分别在不同温度(10、20、30℃)和水活度(0.95、0.98 a_w)下培养不同时间(7、14、21、28、35d)后,运用超高效液相色谱-串联质谱检测DON,3-乙酰化脱氧雪腐镰刀菌烯醇(3-acetyl-deoxynivalenol,3-ADON),15-乙酰化脱氧雪腐镰刀菌烯醇(15-acetyl-deoxynivalenol,15-ADON)和脱氧雪腐镰刀菌烯醇-3-葡萄糖苷(deoxynivalenol-3-glucoside,D3G)的产量。结果在所有培养条件下,原型DON的产量均随时间延长而增加;并于0.98 a_w, 20℃下的第35 d达到最高值100490.0μg/kg;不同培养条件下,修饰型DON的生成情况各不相同,3-ADON、15-ADON和D3G分别于0.98a_w,20℃下的第14、28和35 d达到各自产量最高值(3-ADON:7583.5μg/kg; 15-ADON:592.0μg/kg; D3G:6806.4μg/kg)。此外, 10℃下,D3G/DON比值随时间延长先增高后降低,而20、30℃下D3G/DON比值随时间延长呈指数下降(r~20.90)。结论小麦籽粒中原型和修饰型DON的最适产生条件均为0.98 a_w, 20℃。本研究可为DON及其修饰型的生物合成、日常监管、污染防控等提供理论基础和科学依据。     

乙酰化脱氧雪腐镰刀菌烯醇污染、毒性及转化研究进展

脱氧雪腐镰刀菌烯醇（deoxynivalenol,DON）俗称呕吐毒素,是禾谷镰刀菌等真菌产生的次级代谢产物,是谷物原料及其制品中最常见的污染物之一。DON的产生往往伴随其主要乙酰化衍生物3-乙酰基-DON和15-乙酰基-DON的产生,这些衍生物表现出与DON相似甚至更强的毒性,因而增加了谷物及其制品的食用安全风险。本文简述了DON乙酰化衍生物的产生、检测技术及污染现状,重点分析了DON乙酰化衍生物的毒性及转化研究进展,以期为粮食中DON乙酰化衍生物的降解和防控研究提供理论参考。     

禾谷镰刀菌脱氧雪腐镰刀菌烯醇生物合成及其分子调控研究进展

禾谷镰刀菌是感染小麦、玉米等主要粮食作物的一种重要的病原真菌,在引发严重小麦赤霉病害的同时,可分泌产生脱氧雪腐镰刀菌烯醇（DON）,污染食品后不易被清除,严重威胁人和动物的健康。禾谷镰刀菌产DON的生物合成路径及分子调控机制一直是国内外的研究热点、焦点和难点,也是防控DON的基础。本文综述了禾谷镰刀菌DON生物合成过程中涉及产毒基因簇TRI的各个基因、编码蛋白及其生物学功能,以及目前对禾谷镰刀菌中对呕吐毒素生物合成调控机制的研究进展。这些基础信息将直接为安全控制主要粮食及其制品中真菌毒素污染提供有价值的参考资料。     

脱氧雪腐镰刀菌烯醇酶联免疫检测方法的建立

应用抗脱氧雪腐镰刀菌烯醇单克隆抗体12D1建立了竞争间接ELISA方法,用于检测小麦、玉米中的脱氧雪腐镰刀菌烯醇(DON),最低检出限为20ng/mL,检测范围为20￣460ng/mL。用蒸馏水提取掺合DON(250￣4000ng/g)的小麦样品,回收率为82.1%￣96.6%,变异系数为0.6%￣7.1%。     

脱氧雪腐镰刀菌烯醇人工抗原的研制

本研究利用丁基硼酸封闭DON的7,15-羟基,戊二酸酐酰化3-羟基合成3-HG-DON,通过活泼酯法将3-HG-DON偶联到载体蛋白OVA,制备检测抗原。采用CDI法将DON分子与载体蛋白MBSA偶联制备的免疫抗原免疫3只BALB/c小鼠,经4次免疫后,1号小鼠血清抗体效价达1∶25600,且小鼠抗DON多克隆抗体与DON-HG-OVA的结合能被DON阻断。     

脱氧雪腐镰刀菌烯醇ELISA定量检测试剂盒的研制*

研制了脱氧雪腐镰刀菌烯醇ELISA试剂盒,用于检测谷物粮食中的脱氧雪腐镰刀菌烯醇(Deoxyni-valenol,DON).在抗DON单克隆抗体的基础上,用间接竞争酶联免疫吸附检测试剂盒各项指标.结果为:试剂盒最低检测浓度为20 ng/mL,检测线性范围为50～400 ng/mL,IC<,50> 103 ng/mL.平均加标回收率>80%,批内变异系数小于10%,批间变异系数<15%.用试剂盒测定盲样,其结果与德国拜发试剂盒及免疫亲和柱-高效液相色谱检测结果无显著性差异.说明试剂盒指标符合相关技术要求,具有快速、灵敏、准确、方便等特点.     

脱氧雪腐镰刀菌烯醇生物脱毒的研究进展

脱氧雪腐镰刀茵烯醇作为谷物及其制品中最常见的真菌毒素之一,严重威胁着人类和动物的健康。由于物理、化学脱毒方法存在着营养成分流失、脱毒不彻底等问题,而不能被广泛应用。微生物通过酶促反应将毒素转化成低毒或者无毒物质的生物脱毒方法不仅避免了这些缺点,还具有条件温和、安全环保的优点,是一种理想的脱毒方法。对近年来国内外脱氧雪腐镰刀茵烯醇的生物脱毒研究进展进行了概述,并对脱毒菌株、脱毒酶、脱毒方式及脱毒产物等研究内容作了重点介绍,旨在为脱氧雪腐镰刀菌烯醇的生物脱毒研究提供参考。     

脱氧雪腐镰刀菌烯醇的生物降解研究进展

脱氧雪腐镰刀菌烯醇(deoxynivalenol)作为分布最广泛的镰刀霉毒素之一,不但给全球粮食产业造成巨大经济损失,也给人类健康带来潜在威胁。文中对清除脱氧雪腐镰刀菌烯醇的物理、化学和生物方法进行了综述,为在食品中有效控制其水平提供了思路。     

酿酒过程中脱氧雪腐镰刀菌烯醇的研究

脱氧雪腐镰刀菌烯醇是大麦、麦芽和啤酒中主要的真菌毒素,不仅影响大麦的发芽率、影响啤酒的风味,还会导致啤酒喷涌。本文参照国内外研究资料,阐述了酿酒过程中脱氧雪腐镰刀茵烯醇的变化情况。     

脱氧雪腐镰刀菌烯醇的毒性及脱毒研究进展

脱氧雪腐镰刀菌烯醇(DON)是B型单端孢霉烯族毒素中分布最广的一种,广泛存在于受污染的谷物及饲料中,对人和动物危害很大。本文总结了DON的毒性,包括急、慢性毒性、致癌、致畸、致突变以及细胞毒性等。概述了DON的脱毒方法,包括热处理、辐照和吸附等物理方法,臭氧和化学药物处理等化学方法,以及微生物处理及基因工程等生物方法。同时,分析了当前研究中存在的问题,并对未来的发展趋势进行了展望。      

Growth inhibition of Fusarium graminearum and deoxynivalenol detoxification by lactic acid bacteria and their application in sourdough bread

Eight lactic acid bacteria (LAB) strains were screened for their ability to inhibit Fusarium graminearum (F. graminearum) growth and remove deoxynivalenol (DON). Furthermore, the selected LAB strains were applied as starter cultures to evaluate their performance during the breadmaking process. Lactobacillus plantarum (L. plantarum) AR524 exhibited strong inhibitory activity against F. graminearum growth in a pH-dependent manner and removed up to 40.9% of DON, mainly through cell wall binding. Compared with the control, L. plantarum AR524 inhibited 60.19% of F. graminearum growth and removed 50.53% of DON during breadmaking. The texture properties of the bread were also remarkably improved by L. plantarum AR524, and its shelf life was extended from 3 days to 6 days without the application of any chemical preservatives. Therefore, L. plantarum AR524 shows excellent potential for application as a bioprotective starter culture in bakery products.     

不同培养条件对禾谷镰刀菌产玉米赤霉烯酮的影响

研究不同培养条件对禾谷镰刀菌（Fusarium graminearum）产玉米赤霉烯酮（zearalenone,ZEN）能力的影响。选取不同的培养基配比、培养时间、培养温度、摇床转速及光暗反应对禾谷镰刀菌进行培养。在单因素试验的基础上,分别采用正交试验设计和响应面设计的方法进行统计学分析。结果表明：禾谷镰刀菌的最适培养基为每升超纯水含葡萄糖60 g、KNO3 1.5 g、酵母浸出膏1.0 g、蛋白胨20 g、NaNO3 6.0 g、MgSO4 0.5 g、K2HPO4·3H2O 1.0 g、KCl 0.5 g、Fe2(SO4)3 0.025 g;当摇床转速为92 r/min、照明时间为10 h/d、培养温度为22.9 ℃时,20 d毒素质量浓度可达到249.80 μg/L。     

禾谷镰刀菌发酵液中玉米赤霉烯酮毒素的提取及纯化研究

本研究旨在通过不同萃取剂和层析柱的使用,从禾谷镰刀菌发酵液中提取、纯化玉米赤霉烯酮（zearalenone,ZEN）毒素,以期获得较高纯度的毒素。采用超高效液相色谱串联质谱（ultra-performance liquid chromatography-mass spectrometry,UPLC-MS）分析方法对其效果进行检测。研究结果表明:在单一的萃取剂中,苯的萃取效果最佳,其得率可达到73.20%;采用Daisogel反相层析柱进行纯化,得率可达到69.30%,且样品中的杂峰数目明显减少,由此证明该方法对毒素纯化效果较好。本研究对发展高纯度ZEN毒素的制备技术具有一定的指导意义和参考价值。      

Impact of cycling temperatures on Fusarium verticillioides and Fusarium graminearum growth and mycotoxins production in soybean

BACKGROUND: Fusarium graminearum and F. verticillioides are two very important mycotoxigenic species as they cause diverse diseases in crops. The effects of constant and cycling temperatures on growth and mycotoxin production of these species were studied on soybean based medium and on irradiated soya beans. RESULTS: F. graminearum grew better when was incubated at 15, 20 and 15–20 °C (isothermal or cycling temperature) during 21 days of incubation. Maximum levels of zearalenone and deoxynivalenol (39.25 and 1040.4 µg g^?1, respectively) were detected on soya beans after 15 days of incubation and the optimal temperature for mycotoxin production was 15 °C for zearalenone and 20 °C for deoxynivalenol. F. verticillioides grew better at 25 °C in culture medium and at 15/20 °C and 15/25 °C on soybean seeds. Fumonisin B₁ was produced only in culture medium, and the maximum level (7.38 µg g^?1) was found at 15 °C after 7 days of incubation. CONCLUSION: When growth and mycotoxin production under cycling temperatures were predicted from the results under constant conditions, observed values were different from calculated for both species and substrate medium. Therefore, care should be taken if data at constant temperature conditions are to be extrapolated to real field conditions. Copyright © 2012 Society of Chemical Industry     

姜黄素介导光动力抑制禾谷镰刀菌产ZEN毒素的研究

玉米赤霉烯酮（Zearalenone,ZEN）是广泛污染玉米、小麦、大米等谷物的真菌毒素之一,主要由镰刀菌属产生。该研究选择姜黄素为光敏剂构建光动力技术（Photodynamic Inactivation,PDI）,探究姜黄素浓度、光照能量和溶液pH对PDI抑制禾谷镰刀菌生长及其在玉米中产ZEN的影响。同时,从ZEN毒素含量变化和禾谷镰刀菌失活两个角度分析PDI抑制禾谷镰刀菌产ZEN的机制。结果表明,在50.00 μmol/L姜黄素和43.0 J/cm2光照能量作用下,ZEN含量从空白对照玉米中的1.15 mg/kg降低至光动力处理组中的0.58 mg/kg,降幅达49.56%,且继续增加姜黄素浓度能够完全抑制ZEN的生成。深入分析表明,PDI对禾谷镰刀菌的灭活作用是其抑制玉米中ZEN产生的主要原因,尤其当姜黄素浓度≥70.00 μmol/L,光照能量为43.0 J/cm2时,禾谷镰刀菌被完全灭活。因此,该研究证实光动力技术能够有效地杀灭禾谷镰刀菌,抑制ZEN的产生,为保障农产品质量安全提供了一种新方法。     

Comprehensive evaluation of malt volatile compounds contaminated by Fusarium graminearum during malting

Fusarium graminearum is the most important filamentous fungi in the malting process, and greatly affects malting performance and malt quality. Analysis of the emitted volatiles from F. graminearum mycelium was used to evaluate the malt flavour contaminated by F. graminearum during malting based on solid‐phase microextraction combined with gas chromatography–mass spectrometry. GC–MS analysis of different mycelium samples revealed a broad spectrum of volatile compounds including aldehydes, ketones, alcohols, organic acids and aromatics, which were highly similar to those of barley and malt. Statistical assessment of the data via principal component analysis demonstrated that the major contributors to the time‐dependent dynamic changes in the volatiles were the volatile aldehyde, alcohol and ketone fractions in the contaminated malting process. The results showed that volatile concentration was modulated by the ‐metabolism of the green malt and F. graminearum. Volatile compounds from green malt were influenced by F. graminearum fungi contamination during malting, although some were probably generated by this fungus. Copyright © 2017 The Institute of Brewing & Distilling     

丁香酚、香芹酚和百里香酚对禾谷镰刀菌的抑菌活性及机制

以转录组技术为基础,研究丁香酚、香芹酚和百里香酚对禾谷镰刀菌的抑制作用及作用机理。方法：借助体外抑菌实验测定丁香酚、香芹酚和百里香酚对禾谷镰刀菌菌丝生长、孢子萌发和呕吐毒素生物合成的有效作用浓度;通过测定丁香酚、香芹酚和百里香酚处理后菌丝液的电导率、ATP含量和丙二醛含量进一步从细胞水平探讨其作用位点;通过转录组学阐明丁香酚、香芹酚和百里香酚抑制禾谷镰刀菌生长和毒素合成的分子机制。结果：3 种植物精油活性成分中,百里香酚的抗真菌活性最强。丁香酚、香芹酚和百里香酚可破坏禾谷镰刀菌细胞膜完整性,引起电解质渗漏,能量代谢失衡。此外,3 种植物精油活性成分通过核糖体、线粒体结构和转录组水平上的酶合成发挥对禾谷镰刀菌的抑制作用。     

Effect of fungicides on the development of Fusarium head blight,yield and deoxynivalenol accumulation in wheat inoculated under field conditions with Fusarium graminearum and Fusarium culmorum

The effect of different fungicide treatments on Fusarium head blight (FHB) development, grain yields and deoxynivalenol (DON) accumulation in wheat was evaluated after artificial inoculation under field conditions with a mixture of Fusarium graminearum and F culmorum. The trials were carried out using commercially available products on five different cultivars of soft and durum wheat (Serio, Genio, Bracco, Duilio and Orobel) in two separate experimental fields located in the North of Italy. Treatments with Tiptor^® S (cyproconazole plus prochloraz) and a mixture of Horizon^® 250 EW (tebuconazole) plus Amistar^® 250 SC (azoxystrobin) significantly reduced the FHB disease severity (by between 25 and 77%) and DON content (by between 32 and 89%) in the grain as compared with the inoculated control. Yields (tonne ha^?1) and thousand grain weight (TGW) were higher in plots subjected to fungicide treatments. Tetraconazole (Eminent^® 40 EW) showed a markedly reduced effectiveness compared with the other treatments. Regression analysis showed a strong correlation of disease severity with DON levels (positive correlation) and with yields or TGW (negative correlation) for individual cultivars and locations. Fusarium graminearum, F culmorum and F poae were the species most commonly isolated from all trials, including inoculated and non‐inoculated control plots. Copyright © 2004 Society of Chemical Industry     

Mycoflora and deoxynivalenol in whole wheat grains (Triticum aestivum L.) from Southern Brazil

The fungal species Fusarium graminearum is related to deoxynivalenol (DON) formation. The aim of this study was to evaluate mycoflora and DON occurrence in 53 whole wheat grain samples collected in Southern Brazil during the 2012 crop. Wheat grains showed adequate values of water activity ranging from 0.48 to 0.72, within the required limits of moisture content, ranging from 9.1% to 13.9%. In addition, low counts of fungal colonies, ranging from 10 to 8.2 × 10², were found. For Fusarium genera, there was predominance of Fusarium verticillioides (34%) and F graminearum (30.2%). For Aspergillus species, 37.7% of Aspergillus flavus was determined. Regarding the Penicillium species, Penicillium digitatum (49%) was the most found species. DON was detected in 47.2% (25 out of 53) of the samples analysed, with levels ranging from 243.7 to 2281.3 µg kg^?1 (mean: 641.9 µg kg^?1).