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.

No abstract

No abstract

Methyl formate, a C1 compound reportedly utilized by obligate methylotrophs, gave growth for Methylococcus capsulatus (Texas) but not for Methylosinus trichosporium (OB3b). Both organisms grew on methane, but only M. capsulatus (Texas) utilized methanol; neither organism could use formate as the sole carbon–energy source. Studies with M. capsulatus (Texas) showed that its growth rate on methyl formate was much slower than on methane or methanol, regardless of whether the cells were methane, methanol, or methyl formate grown. Methyl formate underwent "spontaneous" hydrolysis in uninoculated growth medium to yield formic acid and methanol, the latter serving as the actual growth substrate for M. capsulatus (Texas).

The suitability of dimethyl ether as a C1 compound was examined with the obligate methylobacterium Methylococcus capsulatus (Texas). The ether did not support growth and was not formed during growth on methane; it was an inhibitor of growth and oxidation of methane and a poor oxidation substrate for cell suspensions. NADH stimulation of methane, but not dimethyl ether, oxidation occurred in cell extracts.