Rapid characterization of microbial biodegradation pathways by FT-IR spectroscopy

• DOI: 10.1016/j.mimet.2006.04.009
• Publication Date: 2006-06-07T02:55:54Z
• Authors: Wei E. Huang; David Hopper; Royston Goodacre; Manfred Beckmann; Andrew Singer; John Draper
• Keywords: 0301 basic medicine; Pseudomonas putida NCIMB 9869; Principal Component Analysis; 0303 health sciences; pathway; Pseudomonas putida; Metabolic profile; Xylenes; Classification; metabolic profile; biodegradation; Gas Chromatography-Mass Spectrometry; 3. Good health; FT-IR; Cresols; 03 medical and health sciences; Genetic algorithm; classification; Spectroscopy, Fourier Transform Infrared; Biodegradation; genetic algorithm; Pathway

Fourier transform-infrared (FT-IR) spectroscopy has become an important tool for rapid analysis of complex biological samples. The infrared absorbance spectrum could be regarded as a "fingerprint" which is characteristic of biochemical substances. In this study, Pseudomonas putida NCIMB 9869 was grown with either 3,5-xylenol or m-cresol as the sole carbon source, each inducing different metabolic pathways for m-cresol biotransformation. FT-IR spectroscopy was capable of differentiating both induced cultures of P. putida NCIMB 9869 as well as the resulting biotransformation product mixtures. FT-IR spectral analysis indicated that carboxylic acids were key chemicals responsible for distinguishing the products of the two catabolic pathways. Gas chromatography-mass spectrometry (GC-MS) was performed to validate the FT-IR analysis, indicating that two carboxylic acids, 3-hydroxybenzoic acid and 2,5-dihydroxybenzoic acid, were present as m-cresol biotransformation products from 3,5-xylenol-grown cells, but were absent in m-cresol-grown cells. The ability to use FT-IR to rapidly distinguish between biotransformation product mixtures as well as differentially induced bacterial strains suggests this approach might be a valuable tool for screening large biotransformation assays for novel products and metabolic mutants.