河南产麦区小麦镰刀菌毒素污染状况及农民摄入量

检测了赤霉病麦大流行年份及非流行年份小麦中镰刀菌毒素含量,并计算求得农民通过小麦摄入的毒素量。赤霉病麦发病率为34.3%的1985年,小麦中 DON、NIV和 ZEN 含量中位数分别为923.0ppb、128.2ppb 和15.3ppb;每人每日投入量 DON 为528.1微克,NIV 为62.4微克。赤霉病麦发病率<3%的1986年,小麦 DON 含量中位数为14.微克;农民撮入量为9.4微克/人/日。镰刀菌分离结果表明主要为禾谷镰刀菌。值得注意的是发现黄曲霉与禾谷镰刀菌共存于麦粒上。     

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。     

脱氧雪腐镰刀菌烯醇与人类健康

脱氧雪腐镰刀菌烯醇(DON)主要由禾谷镰刀菌(Fusarium graminearum)和黄色镰刀菌(F. culmorum)产生,是一种有很强细胞毒性、胚胎毒性、一定致畸性、弱致癌性,并且影响免疫系统的真菌毒素,严重污染粮谷类食品和饲料,人畜食用被其污染的粮谷后,严重危害健康.就DON的产生、特性、对粮谷类食品的污染、及其危险性分析等方面进行了综述.     

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。     

脱氧雪腐镰刀菌烯醇解毒酶研究进展

脱氧雪腐镰刀菌烯醇（Deoxynivalenol, DON）是镰刀菌属（Fusariums spp.）产生的剧毒次级代谢产物,主要污染小麦、玉米等粮食及其制品,导致了严重的食品安全风险。目前生物酶法去除DON的技术研究,展现出良好的应用前景。综述了国内外关于DON生物转化的生物酶类型、降解机制、产物结构特征、解毒酶挖掘策略,以及解毒酶分子改造等研究现状,并对人工智能应用于真菌毒素解毒酶的相关研究进行了展望,以期为食品和饲料中DON的生物脱毒技术的研发提供参考。     

粮食真菌DNA快速高通量提取方法的建立与应用

目的 建立一种高效、快速、高通量的粮食中真菌DNA提取和分析方法,并应用于小麦产脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)镰刀菌污染状况研究。方法 基于磁珠纯化技术,开发了一种粮食基质中真菌DNA的快速提取方法—月桂酰肌氨酸钠(sodium lauroyl sarcosine, SLS)磁珠法,结合前期采用实时荧光定量PCR法(quantitative real-time PCR, qPCR)和微滴式数字PCR法(droplet digital PCR, ddPCR)建立的小麦中3-乙酰基脱氧雪腐镰刀菌烯醇(3-acetyldeoxynivalenol, 3-ADON)和15-乙酰基脱氧雪腐镰刀菌烯醇(15-acetyldeoxynivalenol, 15-ADON)两种产DON毒素化学型镰刀菌及禾谷镰刀菌复合群分析方法,对其提取效果进行了验证并分析了我国2021年新收获小麦产DON镰刀菌的污染水平。结果 与十六烷基三甲基溴化铵(cetyl trimethyl ammonium bromide,CTAB)法、柱式法试剂盒和磁珠法试剂盒相比较,本研究建立的SLS磁珠法裂解过程无需水浴,配合自动化提取设备工作,整个提取时间小于1 h,对禾谷镰刀菌复合群的提取率最优,而对3-ADON和15-ADON化学型镰刀菌的提取率与经典CTAB法、磁珠法试剂盒没有显著性差异,并且显著性优于柱式法试剂盒。在对2021年收获的120个小麦样品监测结果显示,产DON镰刀菌的生物量与DON毒素水平之间具有极显著的相关性(P<0.01)。结论 SLS磁珠法适用于从基质复杂的粮食样品中提取真菌DNA,操作简便快速、提取率高,更易实现大样本量的分子生物学准确定量检测需求。     

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。     

小麦脱氧雪腐镰刀菌烯醇（DON）快速筛查方法的研究

基于脱氧雪腐镰刀菌烯醇(DON)产毒菌镰刀菌形态特征,以其大型分生孢子为检测目标物,初步建立一种新的小麦DON筛查方法。样品直接用水振荡提取,100目滤布过滤,滤液于显微镜下镜检。检测时间约3 min。对不同感染水平的小麦阳性样品进行镰刀菌大孢子检验(n=6),方法相对标准偏差(RSD)为7.1%~21.6%。对我国小麦主产区的72个小麦样品进行检验,用HPLC法作对照。结果表明,样品中有46个未检出镰刀菌大孢子,占样品总数的63.9%,这些样品DON含量为0~792.4μg/kg,均未超过国家限量标准1 000μg/kg;有26个样品检出大孢子,DON未超标为6个,但均有检出,其余大部分样品镰刀菌生长量与其产生DON的产量呈正相关。由此可见,通过本方法,可快速的对批量小麦DON超标与未超标样品进行筛查区分。     

关于脱氧雪腐镰刀菌烯醇(呕吐毒素)的科学解读

近期在食品药品监管总局组织的食品安全监督抽检中,发现个别粮食及粮食制品脱氧雪腐镰刀菌烯醇（DON,也称呕吐毒素）超过食品安全国家标准限量值。小麦粉中DON超标可能是原料小麦受到该毒素污染,企业对原料把关不严导致。1、谷物中脱氧雪腐镰刀菌烯醇污染在世界范围内广泛存在脱氧雪腐镰刀菌烯醇（Deoxynivalenol,DON）是由产毒真菌产生的一种次级代谢产物,     

脱氧雪腐镰刀菌烯醇及其衍生物检测方法的研究进展

脱氧雪腐镰刀菌烯醇（deoxynivalenol,DON）属B型单端孢霉烯族毒素,主要由镰刀菌在侵染小麦等禾谷类作物的过程中产生。DON是目前谷物及其制品中污染最为普遍的一种真菌毒素,具有明显的毒性,食用被其污染的饲料和食物会对动物和人类产生急性或慢性毒性作用。因此,为了保护消费者健康并最大限度减少经济损失,迫切需要建立高效、简单、快速的检测技术以实现对DON及其衍生物的有效监测。本文对DON及其衍生物常见的定性定量检测方法进行了系统阐述,并对新兴检测技术的创新点及其潜在应用价值进行了讨论分析,以期为DON及其衍生物检测方法的科学选择提供参考。     

Arsenic content of some edible mushroom species

The arsenic contents of 162 fruit body samples of 37 common edible mushroom taxa were analyzed. The samples were gathered from different habitats of Hungary (mainly from mountains) between 1984 and 1999. The arsenic content of the samples was measured by the inductively coupled plasma spectrometry method. Very low [lower than 0.05 mg/kg dry matter (DM)] concentrations were found in the samples of 13 taxa, while higher (or very high) contents were quantified in other common taxa (the highest arsenic content was recorded in the fruit body of Laccaria amethysthea at 146.9 mg/kg DM). The species of eight genera (Agaricus, Calvatia, Collybia, Laccaria, Langermannia, Lepista, Lycoperdon, Macrolepiota) belong to the so-called accumulating taxa, and this tendency is evident on all habitats. This arsenic accumulation capability is found in two orders of Basidiomycetes (Agaricales and Gasteromycetales), which is to say this phenomenon occurs in the families Agaricaceae, Tricholomataceae and Gasteromycetaceae. The accumulating taxa found all have a saprotrophic type of nutrition; arsenic accumulation is not detectable in xilophagous or in mycorrhizal species. The consumption of the accumulating species found has only a low toxicological risk for three reasons: the consumed fresh fruit bodies contain about a tenfold lower arsenic level than the dried ones, the majority of arsenic occurs not in poisonous inorganic, but in less dangerous (or not poisonous) organic forms, and the frequency of consumption is low.     

Organization and localization of the dnaA and dnaK gene regions on the multichromosomal genome of Burkholderia multivorans ATCC 17616

The Burkholderia multivorans strain ATCC 17616 carries three circular chromosomes with sizes of 3.4, 2.5, and 0.9 Mb. To reveal the distribution and organization of the genes for fundamental cell functions on the genome of this bacterium, the dnaA and dnaK gene regions of ATCC 17616 were cloned and characterized. The gene organization of the dnaA region was rnpA-rmpH-dnaA-dnaN-gyrB with a single consensus DnaA-binding box (TTATCCACA) between the rmpH and dnaA genes. This intergenic region, however, did not work as an autonomously replicating sequence in ATCC 17616. On the other hand, the gene organization of the dnaK region was grpE-orf1 (gene for thioredoxin homologue)-dnaK-dnaJ-pabB (gene for p-aminobenzoate synthetase component homologue). A putative heat-shock promoter that showed good homology to the sigma32-dependent promoter consensus sequence in Escherichia coli was found upstream of the grpE gene, suggesting that these five genes constitute an operon. In M9 succinate minimal medium the dnaJ mutant grew more slowly than the wild-type strain, indicating that this operon is functional. Pulsed-field gel electrophoresis and Southern blot analyses indicated that both the dnaA and dnaK gene regions exist as single copies on the 3.4 Mb chromosome.     

Contamination with storage fungi of human food from Cameroon

In a mycological study, a total of 95 human food samples were investigated to evaluate the incidence of fungal contamination in Cameroon by conventional identification method and partly confirmed by DNA sequencing. The isolated fungal spp. were further studied to determine their toxigenic potentials. The investigation revealed the predominance of Aspergillus and Penicillium with 96% of samples contaminated with at least one species of these fungi, whereas the incidence of co-contamination of samples was 85%. Aspergillus flavus and Aspergillus parasiticus (Flavi section) were the most predominant species contaminating mainly maize and peanuts. In addition, P. crustosum and P. polonicum were the most common contaminants belonging to the genus Penicillium. On the other hand, A. ochraceus (Circumdati section) registered a low incidence rate of 5%, including other members of the Aspergillus group. Other members of the genera Rhizopus and Alternaria spp. were also registered in the study. A majority of fungal strains of A. ochraceus, A. parasiticus, P. crustosum and P. polonicum isolated were toxigenic, producing the mycotoxins tested for, while none was detected in cultures of A. fumigatus. The high incidence rate of fungi contamination coupled with their potentials in producing mycotoxins gives a strong indication that the samples tested may likely be contaminated with various mycotoxins. There is need for further study to assess the incidence of mycotoxins contamination in similar food samples.     

Susceptibility of stored product insects to high concentrations of ozone at different exposure intervals

Ozone is a highly reactive gas with insecticidal activity. Past studies have indicated that ozone technology has potential as a management tool to control insect pests in bulk grain storage facilities. The objective of this study was to determine the efficacy of short periods of exposure to high ozone concentrations to kill all life stages of red flour beetle (Tribolium castaneum (Herbst)) (Coleoptera: Tenebrionidae), and Indianmeal moth (Plodia interpunctella (Hübner)) (Lepidoptera: Pyralidae), adult maize weevil (Sitophilus zeamais (Motsch.)) (Coleoptera: Curculionidae) and adult rice weevil (S. oryzae (L)) (Coleoptera: Curculionidae). Insects were treated with six ozone concentrations between 50 and 1800 ppm. The specific objective was to determine minimal time needed to attain 100% mortality. The most ozone-tolerant stages of T. castaneum were pupae and eggs, which required a treatment of 180 min at 1800 ppm ozone to reach 100% mortality. Eggs of P. interpunctella also required 180 min at 1800 ppm ozone to reach 100% mortality. Ozone treatments of 1800 ppm for 120 min and 1800 ppm for 60 min were required to kill all adult S. zeamais and adult S. oryzae, respectively. The results indicate that high ozone concentrations reduce the treatment times significantly over previously described results. Our results also provide new baseline information about insect tolerance to ozone treatment.     

Formation of cereulide and enterotoxins by Bacillus cereus in fermented African locust beans

Afitin, iru and sonru are three spontaneously fermented African locust bean Benin condiments. The fermentation processes are exothermic, with temperatures mostly being above 40 °C. A total of 19 predominant Bacillus cereus isolates from afitin, iru and sonru, were investigated. The enterotoxin genes nhe (A, B, C) were present in all 19 isolates, the hbl (A, C, D) in one (afitin), and the cytK gene in three isolates (afitin). Levels of cytotoxicity to Vero cells and NheA production in BHI-broth was within the range of known diarrheal outbreak strains. Autoclaved cooked African locust beans inoculated with emetic (cereulide producing) B. cereus Ba18H2/RIF supported growth at 25, 30 and 40 °C with highly different maximum cereulide productions of 6 ± 5, 97 ± 3 and 0.04 ± 0.02 μg/g beans, respectively (48 h). For non-autoclaved cooked beans inoculated with 2, 4 and 6 log₁₀B. cereus Ba18H2/RIF spores/g beans, cereulide production was 5 ± 4, 64 ± 8 and 69 ± 34 μg/g beans, respectively at 24 h, while it was 70 ± 43, 92 ± 53 and 99 ± 31 μg/g at 48 h of fermentation at 30 °C. Even though high toxin levels were observed, to date there are no known reports on diarrhea or vomiting due to the consumption or afitin, iru and sonru in Benin, which also according to the present study is likely to be expected from the low levels of cereulide produced at 40 °C.     

Microbial profiles of frozen trimmings and silver sides prepared at Indian buffalo meat packing plants

To assess microbiological quality of buffalo meat trimmings (TT = 114) and silver sides (SS = 41), samples were collected from four different Indian meat packing plants. The aim of this study was: (i) to evaluate standard plate count (SPC), psychrotrophic count (PTC), Enterococcus feacalis count (EFC), Staphylococcus aureus count (SAC) and Escherichia coli count (ECC) and the presence of Salmonella spp. and Listeria monocytogenes; and (ii) also to determine vero toxic E. coli (VTEC) by polymerase chain reaction (PCR). TT samples had significantly higher (P < 0.001) SPC, PTC, EFC, and SAC than SS, while across the meat types there was no difference (P > 0.05) in ECC. E. coli was recovered from 32.4% TT and 19.5% SS samples. The prevalence rate of Salmonella spp. and L. monocytogenes in TT was 1.75% and 0.87%, respectively. But no SS sample was found to be positive for any of these two pathogens. VTEC was found in 2.58% of all the tested samples. This finding suggests that TT contain higher microbes but only small numbers of pathogens of latent zoonotic importance. The present study confirmed the importance of maintaining good process hygiene at meat plants for microbiological status of buffalo meat.     

Assessment of the microbiological safety of salad vegetables and sauces from kebab take-away restaurants in the United Kingdom

The purpose of this study was to establish the microbiological safety of salad vegetables and sauces served in kebab take-away restaurants. Comparison with published microbiological guidelines revealed that 4.7% of 1213 salad vegetable samples were of unsatisfactory microbiological quality due to Escherichia coli and/or Staphylococcus aureus levels at ≥10² cfu g⁻¹. Another 0.3% of salad samples were of unacceptable quality due to S. aureus at ≥10⁴ cfu g⁻¹ (2 samples) or the presence of Salmonella Kentucky (1 sample). Cucumber was the most contaminated salad vegetable with regards to unsatisfactory levels of E. coli (6.0%) or S. aureus (4.5%). Five percent of 1208 sauce samples were of unsatisfactory microbiological quality due to E. coli, S. aureus at ≥10² cfu g⁻¹ and/or Bacillus cereus and other Bacillus spp. at ≥10⁴ cfu g⁻¹. A further 0.6% of sauce samples were of unacceptable quality due to Bacillus spp. (Bacillus subtilis, Bacillus pumilus, Bacillus licheniformis) at ≥10⁵ cfu g⁻¹ or the presence of Salmonella Agbeni (1 sample). More samples of chilli sauce (8.7%) were of unsatisfactory or unacceptable microbiological quality than any other sauce types. The results emphasize the need for good hygiene practices in kebab take-away restaurants handling these types of ready-to-eat products.     

Investigations of the natural microflora of poppy seeds (<Emphasis Type="Italic">Papaver somniferum</Emphasis>) and hazelnut kernels (<Emphasis Type="Italic">Corylus avellana</Emphasis>) including microbiological decomposition

Fatty seeds of Papaver somniferum and Corylus avellana undergo a rapid microbial degradation after being ground. Those bacteria and fungi which are mainly responsible for the microbial decay were identified, and the most important growth and death processes were documented using crucial indicator-organisms. Additionally, an aflatoxin-screening was carried out in order to assess the possible risk-potential of food intoxication. The acid value (indicator for free fatty acids) of poppy seeds and hazelnut kernels was determined during their fermentation in order to document the decomposition of triglycerides.In this study it could be proved that initially a natural decay of oil seeds is caused by bacteria, yeasts and mould fungi. After the bacteria died in the course of time, yeasts and mould fungi dominated the germ spectrum. Bacteria taking part in the degradation were identified as varieties of Staphylococcus xylosus, Enterobacteriaceae and coliforms. Yeasts were identified as Pichia burtonii, and the mould fungi are associated with the genus Alternaria.On account of the absence of the genus Aspergillus in the spectrum of mould fungi, no aflatoxin was produced.