Biodiversity assessment through volatile compound profile analysis in Rhizostoma pulmo

Marine invertebrates are rich sources of bioactive compounds and their biotechnological potential attracts scientific and economic interest. The biochemical processes developed by organisms to live in niche marine environments are highly representative of biochemical diversity. Recent studies, including the application of multi-omics approaches, have identified signaling molecules possibly involved in regulating many intra- and interspecific interactions, including symbiosis, bioactive molecules, reactive species, and volatiles. Cnidarians, a diverse group of marine invertebrates are being studied as possible providers of marine bioactive compounds and some Rhizostomeae also as novel foods with promising results. The study of the volatile profile of jellyfish is pivotal to understand possible chemical communications and is essential for the biochemical composition study aimed at bioprospecting and/or food/feed uses. Here we investigated the volatile profile of Rhizostoma pulmo jellyfish collected in Apulian Ionian Sea, a similar study will be performed on other jellyfish species. Headspace-solid-phase-microextraction (HS-SPME) coupled with gas-chromatography/mass-spectrometry (GC-MS) was used to analyse the volatile profile of jellyfish samples. A detailed analysis of volatile molecules was carried out on whole jellyfish, umbrella, oral arms, stomach content, mucus and surronding seawater, to assess the different chemical profile and study their biosynthetic pathways. The analytical results were subjected to multivariate statistical analysis (Cluster-Heatmap, Principal Component Analysis) and Partial Least Square Correlation analysis that allowed to extrapolate clustering of molecules depending on the samples. Forty-one volatiles belonging to the chemical classes of alcohols, aldehydes, ketones, furans and long chain fatty acids were identified and their role was discussed.