Deoxynivalenol: Occurrence,toxicity, and degradation

Mycotoxins have attracted global attention because of their worldwide distribution and toxic risk. Deoxynivalenol (DON) is a kind of type-B trichothecenes produced by Fusarium fungi and causes great concerns in different fields. The toxic effects of DON and its two acetylated forms of 3-acetyl deoxynivalenol (3-ADON) and 15-acetyl deoxynivalenol (15-ADON) have been studied primarily including hepatotoxicity, intestinal toxicity, nephrotoxicity and reproduction toxicity. Adsorption is one of the widely applied physical methods for DON removal. Different adsorbents including active carbon, montmorillonite and yeast cells have been employed as the materials. Chemical methods involving oxidation and reduction of DON are always conducted by a combination of the ozonation and hydrothermal treatment. Recently, the biological degradation of DON has been intensively studied and found somewhat superior to physical and chemical solutions due to the environmentally friendly property and high specificity. Reported bacteria and the related enzymes that are able to metabolize DON is also comprehensively reviewed, such as the approved Coriobacteriaceae DMS 11798, the well-known Devosia mutans, the PQQ-depend dehydrogenase and the aldo-keto reductase family.     

Granule Sizes of Canna (Canna edulis) Starches and their Reactivity Toward Hydration,Enzyme Hydrolysis and Chemical Substitution

Small and large granule fractions were isolated from canna starch (Canna edulis, green leaf cultivar), and their morphology, physicochemical properties, susceptibility towards granular starch hydrolyzing enzymes and chemical reaction with propylene oxide were investigated. Canna starch consisted of a mixed population of large, medium and small granules; the mean of granule diameter was 47.4 μm. The small granules presented round and polygonal shapes, whereas the large granules had oval and elliptical shapes. Significant variations in digestibility of the various granules size by granular starch hydrolyzing enzymes were observed. During the first 24 h, the hydrolysis rate of small granules was higher than that of native and large granule starches. After 72 h, however, the degree of hydrolysis of small granule, large granule and native starches had reached the extent of 19.6%, 32.0% and 27.2%, respectively. The larger the granule size, the higher the MS obtained when modified with propylene oxide, which was due to the higher swelling power of the large granules. The results obtained from this study suggest that small granules had lower water and chemical affinity when compared with the bigger ones. The difference in the reactivity of small and large granules could be presumably attributed to the starch components (amylose and amylopectin) and their organization of glucan chains in ordered and/or less ordered structure of these two fractions.     

鲀毒鱼类中河鲀毒素直接竞争抑制性酶联免疫吸附试验测定方法的研究

为检测毒鱼类中的河毒素 ,建立了用抗河毒素单克隆抗体检测河样品中河毒素的直接竞争抑制性酶联免疫吸附试验 (ELISA)方法。结果表明 ,直接ELISA法较间接ELISA法灵敏 ,最低检出浓度为 0 1ng mL(每检测孔 0 0 1ng) ,线性范围为 5～ 5 0 0ng mL ,方法的加标回收率为73 0 %～ 118 0 %。本法与传统的小鼠生物试验相比 ,两种方法的测定结果之间在统计学上差异无显著性 (配对t检验 ,P >0 1) ,并具有良好的相关性 (r =0 94 4)。对来自江苏省东海和长江水域的河样品的毒力进行了测定 ,结果表明本方法简单、快速、灵敏 ,完全可以满足实际工作的需要