Enhanced biodegradation of phenolic compounds and cellular fatty acid analysis of bacteria using infrared pyrolysis/gas chromatography-mass spectrometry.

摘要

This thesis consists of two parts. The first part investigates the mechanism of enhanced biodegradation of phenolic compounds. Microorganisms exposed to oleic acid esters of phenol and cresol showed a reduced lag time in the biodegradation of phenol and cresol at concentrations of 1000 ppm. Enhancement of chlorophenol degradation by oleic acid chlorophenyl ester exposed microorganisms was also observed, however, only at the 100 ppm level. Cultures pre-exposed to oleic acid or oleic acid phenyl ester showed an increase in trans fatty acids which has a negative effect on the permeability of the biomembrane and may protect the cells from membrane active compounds such as phenol. Experiments using oleic acid fluorescein ester indicated that the oleic acid moiety carries the phenolic compound across the cell membrane. After hydrolysis of the ester inside the cell, small amounts of the phenolic compound are released and induce the activation of the cell's degradative enzymes.; The second part of this thesis investigates the potential of obtaining fatty acid patterns from whole cell bacteria by in situ derivatization using infrared-pyrolysis/gas chromatography-mass spectrometry. A number of different derivatizing reagents were evaluated and the operating parameters of the system were determined. Fatty acid profiles were obtained from four potential air borne pathogens. The organisms included Bacillus anthracis , Brucella species, abortus, melitensis and suis, Francisella tularensis and Yersinia pestis. The organisms could be identified based on their fatty acid profiles.