Departamento de Química Analítica, Instituto de Investigación en Ingeniería de Aragón (I3A), Grupo GUIA, Universidad de Zaragoza , Zaragoza E-50018, Spain.
Anal Chem. 2016 May 3;88(9):4772-9. doi: 10.1021/acs.analchem.6b00116. Epub 2016 Apr 11.
Raman imaging spectroscopy is a nondestructive analytical method that can be a useful tool to obtain detailed information about the molecular composition and morphology of biological samples. Its high spatial resolution was used to collect spectra of Aspergillus ochraceus, a mold producer of ochratoxin A (OTA), in order to investigate the cell damage caused on it by the action of the antimicrobial benzyl isothiocyanate (BITC). The study was performed in both direct contact and vapor phase, in order to check the use of BITC as active agent in food packaging material. The results showed that there were morphologic alteration and a characteristic Raman spectrum on spore and hyphae exposed to BITC. BITC was accumulated in the mold cells where it caused an enormous amount of alterations in cellular components (lipids, proteins, saccharides, amino acids...) and cellular functions (cell cycle, respiration, metabolism, transcription of genes, fluidity of the cellular wall). All these structural, composition, and metabolic changes will affect the production of OTA. Pattern recognition with chemometrics using principal component analysis (PCA) demonstrated an excellent separation between control and BITC treated samples, both in spores and hyphae. PCA results also showed two different affection levels when samples were exposed to BITC in the vapor phase.
拉曼成像光谱学是一种无损分析方法，可以作为获取生物样本分子组成和形态详细信息的有用工具。它具有较高的空间分辨率，用于收集赭曲霉（一种产生赭曲霉毒素 A（OTA）的霉菌）的光谱，以研究其对抑菌剂苄基异硫氰酸酯（BITC）的作用所造成的细胞损伤。该研究在直接接触和气相两种情况下进行，以检查 BITC 作为食品包装材料中活性物质的用途。结果表明，接触 BITC 的孢子和菌丝出现了形态改变和特征性拉曼光谱。BITC 在霉菌细胞中积累，导致细胞成分（脂质、蛋白质、糖类、氨基酸等）和细胞功能（细胞周期、呼吸、代谢、基因转录、细胞壁流动性）发生巨大变化。所有这些结构、组成和代谢变化都会影响 OTA 的产生。使用主成分分析（PCA）的化学计量学模式识别在孢子和菌丝中均能极好地区分对照和 BITC 处理的样品。PCA 结果还表明，当样品在气相中接触 BITC 时，会有两种不同的影响程度。
