發展以基質輔助雷射脫附游離質譜法快速檢測污染食品中黴菌的方法

Abstract

基質輔助雷射脫附游離/飛行時間質譜法為一具有相當高的靈敏度，分析質量範圍廣，且操作簡易的質譜法，常應用在生化分子的質量分析上。當用在直接分析微生物時，可根據在不同菌株中所得到之質譜圖離子訊號分佈建立指紋質譜圖，及尋找其中特有之生物標幟，以做為辨認微生物種類的依據，尤其黴菌孢子之基質輔助雷射脫附游離質譜圖相當簡單，不同屬種之孢子具有高度特異性之生物標幟離子，可以用以區分不同黴菌菌種。 本計劃將利用基質輔助雷射脫附質譜法分析常污染食品如咖啡豆、果汁及水果之青黴菌屬(Penicillium)、麴菌屬(Aspergillus)的孢子，建立菌屬之特異指紋質譜圖及生物標幟離子，以發展可以快速辨認污染食品之微生物的方法為目標，此研究方向有別於傳統方法是以偵測黴菌的二次代謝物為主，為一更直接且快速的方法。

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI/TOFMS) has been frequently used in the analysis of biomolecules owing to the advantages of high sensitivity, wide mass range, and ease-of-use. MALDI/MS can be used directly to characterize microorganisms based on the biomarker ions and the fingerprint pattern in the mass spectra of different microorganism strains. In particularly, the high reproducibility and simplicity of the MALDI mass spectra of fungus spores can be employed to the characterization of different strains of fungi. In this proposal, we plan to construct a MALDI mass spectral database of fingerprint mass spectra and biomarker ions representing for different Pencillium and Aspergillus species. These two species are frequently found in the food such as coffee beam, juice, and fruits. Based on the establishment of the mass spectral database of fungus spores, a rapid screening method of food for contamination by fungal spores can be expected. This approach provides a more rapid and direct means than that of the conventional method, which generally uses the secondary metabolites of fungi as the target analytes.