中文摘要：无创、易用、成本效益高的技术为快速检测商品中的致癌真菌代谢物，即黄曲霉毒素提供了一个有用的选择。光谱技术的应用是该领域一个相对较新的发展。特别是荧光高光谱成像，提供了一种潜在的检测产毒黄曲霉感染的玉米中黄曲霉毒素的快速无创方法。先前研究表明，基于全粒的外部荧光发射，受到黄曲霉毒素污染的整粒玉米显示的光谱特征不同于未污染籽粒。本研究检查了时间对产毒和不产毒黄曲霉感染的玉米籽粒横切面内部荧光光谱发射的影响，以便阐明某些黄曲霉毒素污染的玉米粒发出的荧光信号与真菌侵染产生黄曲霉毒素之间的相互作用。结果表明，荧光峰移和强度,以及时间对基于光谱特征区分产毒和不产毒真菌都很重要。还揭示了产毒和不产毒黄曲霉菌株在玉米粒内定殖的可能的差异，是一种用特定时间点的荧光光谱区分菌株的电位窗口。
外文摘要：Non-invasive, easy to use and cost-effective technology offers a valuable alternative for rapid detection of carcinogenic fungal metabolites, namely aflatoxins, in commodities. One relatively recent development in this area is the use of spectral technology. Fluorescence hyperspectral imaging, in particular, offers a potential rapid and non-invasive method for detecting the presence of aflatoxins in maize infected with the toxigenic fungus Aspergillus flavus. Earlier studies have shown that whole maize kernels contaminated with aflatoxins exhibit different spectral signatures from uncontaminated kernels based on the external fluorescence emission of the whole kernels. Here, the effect of time on the internal fluorescence spectral emissions from cross-sections of kernels infected with toxigenic and atoxigenic A. flavus, were examined in order to elucidate the interaction between the fluorescence signals emitted by some aflatoxin contaminated maize kernels and the fungal invasion resulting in the production of aflatoxins. First, the difference in internal fluorescence emissions between cross-sections of kernels incubated in toxigenic and atoxigenic inoculum was assessed. Kernels were inoculated with each strain for 5, 7, and 9 days before cross-sectioning and imaging. There were 270 kernels (540 halves) imaged, including controls. Second, in a different set of kernels (15 kernels/group; 135 total), the germ of each kernel was separated from the endosperm to determine the major areas of aflatoxin accumulation and progression over nine growth days. Kernels were inoculated with toxigenic and atoxigenic fungal strains for 5, 7, and 9 days before the endosperm and germ were separated, followed by fluorescence hyperspectral imaging and chemical aflatoxin determination. A marked difference in fluorescence intensity was shown between the toxigenic and atoxigenic strains on day nine post-inoculation, which may be a useful indicator of the location of aflatoxin contamination. This finding suggests that both, the fluorescence peak shift and intensity as well as timing, may be essential in distinguishing toxigenic and atoxigenic fungi based on spectral features. Results also reveal a possible preferential difference in the internal colonization of maize kernels between the toxigenic and atoxigenic strains of A. flavus suggesting a potential window for differentiating the strains based on fluorescence spectra at specific time points.
外文关键词：aflatoxin；Aspergillus flavus；internal fluorescence；hyperspectral imaging；maize
作者：Hruska, Z；Yao, HB；Kincaid, R；Brown, RL；Bhatnagar, D；Cleveland, TE；AF Hruska, Zuzana；Yao, Haibo；Kincaid, Russell；Brown, Robert L.
作者单位：Mississippi State Univ
期刊名称：FRONTIERS IN MICROBIOLOGY
期刊影响因子：4.165
出版年份：2017
出版刊次：-
点击下载：接种了产毒和不产毒黄曲霉的玉米籽横截面与黄曲霉毒素污染相关的内部荧光发射的时间效应