The Mediterranean gilthead seabream (Sparus aurata) is a widely consumed seafood product, with global production reaching 354,920 tonnes in 2022, primarily from aquaculture (FAO, 2024). However, seabream is microbiologically sensitive and highly perishable, which leads to significant food waste. Following slaughter, seabream flesh becomes vulnerable to microbial colonization, leading to the development of a specific endogenous microbiota.

Some bacteria play a role in spoilage, degrade the product quality by generating metabolites that alter its sensory characteristics. Biopreservation is a soft preservation technic which seeks to modulate the microbiota of food product to slow down spoilage or pathogen growth. This technic involves inoculating the product with microorganisms or metabolites that exhibit antimicrobial activity (Passerini et al., 2021).

In the frame work of the European project Foodguard, five protective lactic acid bacteria (LAB) were tested on seabream fillets stored under modified atmosphere packaging at 8°C during 11 days. During these shelf-life experiments, LAB strains effects on the microbial community and seabream quality were assessed on 110 samples using: classical microbiological enumeration techniques, 16S amplicons sequencing approach, biochemistry analysis and sensory evaluations conducted by an expert panel.

Results show that three LAB strains significantly reduced the presence of seabream spoilage-associated bacteria such as Brochothrix, Pseudomonas, and members of the Enterobacteriaceae family. Sensory analyses confirmed the beneficial effects of these strains, which helped maintain the fillet quality for up to 8 days of storage. Multi-omics analyses were conducted to correlate microbiota composition and dynamics with biochemical profiles, as well as sensory scores and attributes, thereby revealing biologically relevant and robust molecular signatures.