NMR-Based Microbial Metabolomics and the Temperature-Dependent Coral Pathogen Vibrio coralliilyticus

Abstract

Coral bleaching occurs when the symbioses between coral animals and their zooxanthellae is disrupted, either as part of a natural cycle or as the result of unusual events. The bacterium Vibrio coralliilyticus (type strain ATCC BAA-450) has been linked to coral disease globally (for example in the Mediterranean, Red Sea, Indian Ocean, and Great Barrier Reef) and like many other Vibrio species exhibits a temperature-dependent pathogenicity. The temperature-dependence of V. corallillyticus in regard to its metabolome was investigated. Nuclear magnetic resonance (NMR) spectra were obtained of methanol-water extracts of intracellula rmetabolites (endometabolome) from multiple samples of the bacteria cultured into late stationary phase at 27 degrees C (virulent form) and 24 degrees C (avirulent form). The spectra were subjected to principal components analysis (PCA), and significant temperature-based separations in PC1, PC2, and PC3 dimensions were observed. Betaine, succinate, and glutamate were identified as metabolites that caused the greatest temperature-based separations in the PC scores plots. With increasing temperature, betaine was shown to be down regulated, while succinate and glutamate were up regulated.

1H NMR-based metabolomic observation of a two-phased toxic mode of action in Eisenia fetida after sub-lethal phenanthrene exposure

“…[10,40,41] Betaine stabilises cellular metabolic functions under varying conditions of stress by enhancing the water retention of cells and by replacing inorganic salts. [37,42,43] Betaine significantly (at a ¼ 0.05) increased at the lowest exposure of 0.025 mg cm À2 (Figs 3a, 4h). However, the increase in betaine at exposures 40.025 mg cm À2 was not significant (Fig.…”

“…[36] A t-test (twotailed, equal variances) was also performed on the first and second component PCA and PLS-DA scores to determine if there was a significant difference between the scores of the controls and the exposed worms at a ¼ 0.05. [37] Corresponding PCA loadings plots, which show the relative weight for each bucket, were also acquired for each of the PCA scores plots to identify the metabolites that were contributing to the separation between the scores of the control and exposed earthworms. Both PCA and PLS-DA showed similar trends in discrimination ( Fig.…”

Unraveling the concentration-dependent metabolic response of Pseudomonas sp. HF-1 to nicotine stress by 1H NMR-based metabolomics

“…NMR has been extensively used in microbial metabolomics because it is intrinsically nonselective in metabolite detection, quantitative, reproducible and rich in structural information. NMR-based metabolomics has already been established as a powerful tool for microbial differentiation and identification (Himmelreich et al 2003;Allen et al 2003;Bundy et al 2005), metabolic situation (Gjersing et al 2007;Halouska et al 2007;Son et al 2009) and the identification of complex biological system responses to environmental factors on the metabolite level (Boroujerdi et al 2009;Tremaroli et al 2009). This approach has also been applied in environmental studies with comprehensive characterizations of other organism metabolic responses to stressors such as metals (Tjeerdema 2008), organic pollutants (McKelvie et al 2009Brown et al 2010) and temperature (Malmendal et al 2006).…”

Genomic Approaches in Marine Biodiversity and Aquaculture

“…Metabolite profiling by MS has also recently been used on amussel (Mytiluscalifornianus) to study its metabolism in both the aerobic and anaerobic phases of its life cycle (Connor & Gracey, 2012). Similarly, NMR-based metabolic profiles have been employed to determine the metabolites responsible for the variation in the metabolic profi le of pathogenic Vibrio coralliilyticus under extreme natural environments (Boroujerdi et al, 2012), including variable temperatures (Boroujerdi et al, 2009).…”