Mycotoxins最新文献_第4页

Type B trichothecenes-the relationship between slight structural changes and toxicity B型毛霉烯-轻微结构变化与毒性的关系

Mycotoxins Pub Date : 2016-01-01 DOI: 10.2520/MYCO.66.45

Tadahiro Suzuki, Y. Iwahashi

引用次数: 0

The collection and study of the biological active substances from microorganisms 微生物活性物质的收集与研究

Mycotoxins Pub Date : 2016-01-01 DOI: 10.2520/MYCO.66.81

F. Shibuya, Y. Shiono

引用次数: 1

Contribution of gliotoxin to aspergillosis 胶质毒素对曲霉病的作用

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.109

Takahito Toyotome

引用次数: 0

New approach to screen for fungal allergens using whole genomic sequence data in Kuro-koji molds 利用黑曲霉菌全基因组序列数据筛选真菌过敏原的新方法

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.115

Naoki Kobayashi

引用次数: 0

Evolution of a fumonisin biosynthetic gene cluster in Fusarium fujikuroi species complex 藤黑镰刀菌种复合体中一个伏马菌素生物合成基因簇的进化

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.121

H. Suga

引用次数: 1

The mode of phytotoxic action of trichothecenes during plant-Fusarium interaction; our approach to detoxification of trichothecenes in cereals. 植物与镰刀菌相互作用中毛霉烯的植物毒性作用模式我们对谷物中毛霉烯解毒的研究。

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.143

T. Nishiuchi, M. Kimura, Kazuhiro Sato

引用次数: 0

An electron microscopic study of microorganisms: from influenza virus to deep-sea microorganisms 微生物的电子显微镜研究:从流感病毒到深海微生物

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.81

M. Yamaguchi

{"title":"An electron microscopic study of microorganisms: from influenza virus to deep-sea microorganisms","authors":"M. Yamaguchi","doi":"10.2520/MYCO.65.81","DOIUrl":"https://doi.org/10.2520/MYCO.65.81","url":null,"abstract":"Three topics from electron microscopic studies of microorganisms car-ried out in my laboratory in recent ten years are described. 1) Influenza A virus was observed in water by an ice-embedding method using phase contrast electron microscopy developed in Japan. Virions appeared as spherical or elongated particles consisting of spikes, an envelope, and a core with high contrast. 2) A new term the “structome” was introduced and defined as “the quantitative and three-dimensional structural information of a whole cell at electron microscopic level.” We performed structome analyses of Saccharomyces cerevisiae by using freeze-substitution and serial ultrathin sectioning electron microscopy. We found that there were one to four mitochondria and about 195,000 ribosomes in a cell. 3) In the deep-sea off the coast of Japan, we discovered a unique microorganism appearing to have cellular features intermediate between prokaryotes and eukaryotes. The organism, named as the Myojin parakaryote, was two orders of magnitude larger than a typical bacterium and had a large “nucleoid”, surrounded by a single layered “nucleoid membrane”, and bacteria-like “endosymbionts”, but it lacked mitochondria. This organism exemplifies a potential evolutionary path between prokaryotes and eukaryotes, and the presence of the organism supports the endosymbiotic theory for the origin of mitochondria and the karyogenetic hypothesis for the origin of the nucleus. These studies show that the electron microscopy is a powerful tool for studying a wide range of problems of microorganisms. The ultrastructure of frozen-hydrated influenza A virus was examined by Zernike phase contrast electron microscopy. Using this new technique, the virions were clearly observed with high contrast and appeared as spherical or elongated particles consisting of peripheral spikes, an envelope, and a core. Not only lipid bilayers but also individual glycoprotein spikes on viral envelopes were clearly resolved. About 450 glycoprotein spikes were present in an average-sized spherical virion. Eight ribonucleoprotein complexes, that is, a central one surrounded by seven others, were distinguished in one viral particle. Thus, Zernike phase contrast electron microscopy is a powerful tool for resolving the ultrastructure of viruses in natural and hydrated state, because it enables high-contrast images of ice-embedded particles. in state was 1) , . cell at electron microscopic level.\" In the present study, we performed structome analysis of Saccharomyces cerevisiae , one of the most widely researched biological materials, by using freeze-substitution and serial ultrathin sectioning electron microscopy. Our analysis revealed that there were one to four mitochondria and about 195,000 ribosomes in a cell and 13-28 endoplasmic reticula/Golgi apparatus, which do not form networks in the cytoplasm in G1 phase. The nucleus occupied 10.1 % of the cell volume, the cell wall occupied 17.7 %, the vacuole occupied 4.0 %, the cyt","PeriodicalId":19069,"journal":{"name":"Mycotoxins","volume":"43 1 1","pages":"81-99"},"PeriodicalIF":0.0,"publicationDate":"2015-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73195652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Occurrence of aflatoxin M1 in commercial powdered milk in Bangkok, Thailand 泰国曼谷市商品奶粉中黄曲霉毒素M1的发生

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.75

Manita Soontornjanagit, O. Kawamura

引用次数: 4

Effects of volatile compounds produced by plants on fungal growth and the production of mycotoxins 植物挥发性化合物对真菌生长和真菌毒素产生的影响

Mycotoxins Pub Date : 2015-07-31 DOI: 10.2520/MYCO.65.131

T. Taguchi, A. Ishihara, H. Nakajima

{"title":"Effects of volatile compounds produced by plants on fungal growth and the production of mycotoxins","authors":"T. Taguchi, A. Ishihara, H. Nakajima","doi":"10.2520/MYCO.65.131","DOIUrl":"https://doi.org/10.2520/MYCO.65.131","url":null,"abstract":"Fungal contamination of food is one of the most important food safety concerns, however effective techniques to prevent fungal contamination and/or control fungal growth in foods have not yet been established. Some endogenous volatile compounds in plants have antibacterial and/or antifungal activities. For example, when some plants are damaged, they release aliphatic aldehydes with six or nine carbons to protect themselves from microbial infection. Patulin is the major mycotoxin that contaminates apples and apple juice worldwide, and it is regulated in many countries. Patulin has been shown to be immunotoxic and neurotoxic by animal experiments. Many species of Penicillium and Aspergillus produce patulin, but P. expansum is the most typical species responsible for patulin contamination in apples. We attempted to assess the effects of aliphatic aldehydes on P. expansum . Aliphatic aldehydes composed of 3–6 carbons bearing an E double bond at the α -position completely inhibited the fungal growth and suppressed colony formation from spores at relatively low concentrations. On the basis of the structure-activity relationship, the antifungal activity of the compounds is probably attributable to the interaction of the aldehyde group with biological macromolecules. On the other hand, aliphatic aldehydes with 8–10 carbons stimulated patulin production by P. expansum . The results of a reverse transcription-quantitative polymerase chain reaction analysis suggested that the stimulation was partially due to enhanced transcription of some patulin biosynthetic genes. The effects of volatiles of apple on patulin production by P. expansum were also studied. Some volatile compounds, that is, 2-mehtylbutanoic acid and ethyl 2-methylbutanoate, were found to stimulate patulin production. These findings will contribute to the development of new techniques to prevent and control fungal and mycotoxin contamination of foods.","PeriodicalId":19069,"journal":{"name":"Mycotoxins","volume":"15 1","pages":"131-142"},"PeriodicalIF":0.0,"publicationDate":"2015-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81891033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Evaluation of toxicities of 7-hydroxyisotrichodermin and 8-hydroxyisotrichodermin, shunt intermediates in the biosynthetic grid of deoxynivalenol, by using a sensitive yeast assay 7-羟基异木霉素和8-羟基异木霉素，脱氧雪腐镰刀醇生物合成网格中的分流中间体的毒性评价，采用灵敏的酵母试验

Mycotoxins Pub Date : 2015-01-31 DOI: 10.2520/MYCO.65.7

Kentaro Kamata, A. Tanaka, Kazuyuki Maeda, Ryo Takushima, Hiroki Sato, Shunichi Aikawa, Yasuhiko Yoshida, M. Kimura, N. Takahashi-Ando

{"title":"Evaluation of toxicities of 7-hydroxyisotrichodermin and 8-hydroxyisotrichodermin, shunt intermediates in the biosynthetic grid of deoxynivalenol, by using a sensitive yeast assay","authors":"Kentaro Kamata, A. Tanaka, Kazuyuki Maeda, Ryo Takushima, Hiroki Sato, Shunichi Aikawa, Yasuhiko Yoshida, M. Kimura, N. Takahashi-Ando","doi":"10.2520/MYCO.65.7","DOIUrl":"https://doi.org/10.2520/MYCO.65.7","url":null,"abstract":"Fusarium graminearum causes a disease of wheat and barley known as Fusarium head blight. It contaminates the grains with trichothecene mycotoxins such as deoxynivalenol (DON). As shunt intermediates in the DON biosynthetic pathway, 7-hydroxyisotrichodermin (7-HIT) and 8-hydroxyisotrichodermin (8-HIT) are known. However, their activities have not been previously evaluated. In this study, we performed toxicity assays of these trichothecenes by using a sensitive yeast bioassay that we have recently established. The IC50 of 7-HIT and 8-HIT were in the range of 20-40 μg/ml, while the IC50 of DON was approximately 1.5 μg/ml. Although the toxicity of these shunt metabolites remains to be investigated in animal systems, our present data indicate that 7-HIT and 8-HIT may not be major issues that require regulation in agricultural products. Fusarium head blight (FHB) is a serious disease of wheat and barley caused mainly by Fusarium graminearum and Fusarium culmorum. The infected grains are often contaminated with trichothecenes such as deoxynivalenol (DON; Fig. 1), nivalenol (NIV), and acetylated derivatives thereof1),2),3). These mycotoxins, which are characterized by the presence of a ketogroup at C-8, are collectively termed type B trichothecenes. The toxicities of these mycotoxins are significantly affected by the side-chain oxygenation and acetylation patterns4),5). With regard to DON, a provisional limit (1.1 ppm in wheat in Japan) has been set in many countries to ensure the safety of cereal grains and processed products. DON biosynthesis starts with cyclization of alltrans-farnesyl pyrophosphate to give trichodiene, followed by four oxygenation steps and a second nonenzymatic cyclization yielding isotrichodermol. As major intermediates of the DON pathway, isotrichodermol, isotrichodermin, 15-deacetylcalonectrin, calonectrin, and 3,15-diacetyldeoxynivalenol are known6),7). The toxicities of these major intermediates were previously evaluated using either animal or plant systems8). However, the toxicities of shunt intermediates of DON, such as 7-hydroxyisotrichodermin (7-HIT) and 8hydroxyisotrichodermin (8-HIT) (see Fig. 1) have not been examined so far. Previously, we developed a sensitive yeast bioassay for trichothecenes by utilizing a gene deletion mutant of three resistance genes against trichothecenes: pdr5, erg6, and rpb4 in Saccharomyces cerevisiae BY47429). Fig. 1 Chemical structures of deoxynivalenol (DON), 7hydroxyisotrichodermin (7-HIT), and 8-hydroxyisotrichodermin (8-HIT).","PeriodicalId":19069,"journal":{"name":"Mycotoxins","volume":"4 1","pages":"7-9"},"PeriodicalIF":0.0,"publicationDate":"2015-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84672322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3