Investigating the Effects of Protein Contents on Microorganism Identification by HPLC-Mass Spectrometry and Protein Database Searches
| Autor: | Po-Hsi Hsu, 徐勃曦 |
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| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 High performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) has been employed for separation and detection of protein biomarkers from E. coli samples. LC-MS is suitable for microbial identification because it can couple on-line with sample clean-up devices and is readily amenable to automation. In this work, we have investigated the effects of sample preparation methods on the detection of bacterial proteins by LC-MS. Many factors effect the degree of variations in the protein patterns (i.e. number and mass of proteins). For example, changing the polarity as well as pH of the extraction solvent may control the number of detected proteins. It is also noted that the protein patterns can vary even when the total ion chromatography plots seem to be the same under the same preparation conditions. In spite of the variation in protein patterns, all the database search results show that the best matches come from the correct microorganism. Direct MS analysis of microorganisms has also been carried out without prior LC separation. Based on the results of the solvent effect study in the LC-MS work, a 70% acetonitrile /0.1% formic acid solution was used to extract biomarkers from Bacillus subtilis、Streptococuus bovis、Xanthomonas campestris and Staphylococcus aureus. All the spectra showed different finger print biomarkers that differentiated the microorganisms at both the genus and species levels. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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