AUTHOR=Frizzo Riccardo , Bortoletto Enrico , Riello Tobia , Leanza Luigi , Schievano Elisabetta , Venier Paola , Mammi Stefano 

TITLE=NMR Metabolite Profiles of the Bivalve Mollusc Mytilus galloprovincialis Before and After Immune Stimulation With Vibrio splendidus

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2021.686770

DOI=10.3389/fmolb.2021.686770

ISSN=2296-889X

ABSTRACT=<p>The hemolymph metabolome of <italic>Mytilus galloprovincialis</italic> injected with live <italic>Vibrio splendidus</italic> bacteria was analyzed by <sup>1</sup>H-NMR spectrometry. Changes in spectral hemolymph profiles were already detected after mussel acclimation (3 days at 18 or 25 °C). A significant decrease of succinic acid was accompanied by an increase of most free amino acids, mytilitol, and, to a smaller degree, osmolytes. These metabolic changes are consistent with effective osmoregulation, and the restart of aerobic respiration after the functional anaerobiosis occurred during transport. The injection of <italic>Vibrio splendidus</italic> in mussels acclimated at 18°C caused a significant decrease of several amino acids, sugars, and unassigned chemical species, more pronounced at 24 than at 12 h postinjection. Correlation heatmaps indicated dynamic metabolic adjustments and the relevance of protein turnover in maintaining the homeostasis during the response to stressful stimuli. This study confirms NMR-based metabolomics as a feasible analytical approach complementary to other omics techniques in the investigation of the functional mussel responses to environmental challenges.</p>