Detection of the dipicolinic acid biomarker in Bacillus spores using Curie-point pyrolysis mass spectrometry and fourier transform infrared spectroscopy
Detection of the dipicolinic acid biomarker in Bacillus spores using Curie-point pyrolysis mass spectrometry and fourier transform infrared spectroscopy
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DOI：
10.1021/ac990661i
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发表时间：
2000-01-01
影响因子：
7.4
通讯作者：
Logan, NA
中科院分区：
文献类型：
--
作者：
Goodacre, R;Shann, B;Logan, NA
36株产芽孢杆菌经多相分类鉴定，分别属于解淀粉芽孢杆菌、蜡状芽孢杆菌、地衣芽孢杆菌、巨大芽孢杆菌、枯草芽孢杆菌（包括尼日尔芽孢杆菌和球形芽孢杆菌）、球形芽孢杆菌和侧孢短杆菌在营养琼脂上无菌生长，通过居里点热解质谱（PyMS）和漫反射-吸收傅里叶变换红外光谱（FT-IK）分析营养体和孢子化生物质，基于规则归纳和遗传规划的化学计量学方法用于正确确定生理状态（营养细胞或孢子），这些方法产生的数学规则可以简单地用生化术语解释。对于PyMS，发现m/z 105是特征性的，并且是从吡啶二羧酸的热解获得的吡啶酮离子（C6 H3 ON +（吡啶-2，6-二羧酸; DPA），一种存在于孢子中但不存在于营养细胞中的物质;这用热解-气相色谱/质谱法证实，此外，在FT-IR分析中，发现在距离DPA 1447-1439 cm（-1）处的吡啶环振动是孢子的高度特征。因此，尽管原始数据集同时记录了来自全细胞的数百个光谱变量，但可以使用简单的生物标志物来快速和明确地检测这些生物体的孢子。
Thirty-six strains of aerobic endospore-forming bacteria confirmed by polyphasic taxonomic methods to belong to Bacillus amyloliquefaciens, Bacillus cereus, Bacillus licheniformis, Bacillus megaterium, Bacillus subtilis (including Bacillus niger and Bacillus globigii), Bacillus sphaericus,and Brevi laterosporus were grown axenically on nutrient agar, and vegetative and sporulated biomasses were analyzed by Curie-point pyrolysis mass spectrometry (PyMS) and diffuse reflectance-absorbance Fourier-transform infrared spectroscopy (FT-IK), Chemometric methods based on rule induction and genetic programming were used to determine the physiological state (vegetative cells or spores) correctly, and these methods produced mathematical rules which could be simply interpreted in biochemical terms. For PyMS it was found that m/z 105 was characteristic and is a pyridine ketoniun ion (C6H3ON+) obtained from the pyrolysis of dipicolinic acid (pyridine-2,6-dicarboxylic acid; DPA), a substance found in spores but not in vegetative cells; this was confirmed using pyrolysis-gas chromatography/mass spectrometry, In addition, a pyridine ring vibration at 1447-1439 cm(-1) from DPA was found to be highly characteristic of spores in FT-IR analysis. Thus, although the original data sets recorded hundreds of spectral variables from whole cells simultaneously, a simple biomarker can be used for the rapid and unequivocal detection of spores of these organisms.