Biology subjects

Bachi, G.

Publications and source records attributed to Bachi, G..

2 recordsLinked to original sources

bioRxiv2025

Does ecological restoration align prokaryotic community structure with natural references across European coastal wetlands?

AbstractCoastal wetlands are crucial for biodiversity and act as critical buffers for carbon sequestration and atmospheric greenhouse gases (GHG) concentrations, yet their degradation often turns them into GHG sources. Restoration is widely implemented to recover these services, but it remains unclear whether interventions successfully reestablish the microbial functional diversity underpinning biogeochemical cycles. We tested the hypothesis that restoration aligns prokaryotic community structure with natural references, analyzing, a European gradient of coastal wetlands, comparing well-preserved, altered, and restored sites in water and sediment. Using 16SrRNA-metabarcoding and IndVal-Analysis, we characterized community assembly identifying diagnostic functional consortia. Results revealed a marked difference in water and sediment recovery after restoration. Bacterioplankton communities rapidly converge to natural references, while sediment microbiome displayed significant "ecological memory". Restored wetlands show sediment communities structurally distinct from well-preserved, retaining alteration-associated guilds decades. Results support the initial hypothesis: restoration processes in coastal wetlands can re-establish communities and metabolisms resembling well-preserved conditions in the water in the short term, while sediments retain microbial communities and metabolisms inherited from altered conditions for a long time. Future strategies must integrate active sediment interventions using molecular bioindicators to validate not only the landscape appearance, but the effective reactivation of ecosystem processes and microbiota-related services.

ecology↗

bioRxiv2024

Unveiling the control of N and P on DOM fate in a Mediterranean coastal environment

Dissolved organic matter (DOM) and heterotrophic prokaryotes (HP) are key players in the oceanic carbon cycle. Although several biotic and abiotic factors controlling DOM fates are known, the hierarchy of their respective influences is still debated. Two contrasting Mediterranean coastal sites were sampled: a harbour under strong continental and anthropogenic influence (T) and an open coastal area (G). Interestingly, similar dissolved organic carbon (DOC) concentrations were observed in both samples. However, they showed marked differences in dissolved inorganic nitrogen and organic phosphorus concentrations (60-fold and 80% higher value in T), as well as in DOM optical properties and molecular composition. Incubation experiments were performed to expose the HP communities of each site to dissolved substances from T and G for three weeks. DOC removal was similar (-10 %) regardless HP origin and dissolved substances characteristics. HP growth and their maximal abundance were higher (+ 300 %) with dissolved substances from T, regardless HP origins. This indicates different fates of DOC processed by microbial communities as a function of abiotic determinants. Higher HP growth was associated to elevated initial content and higher consumption of inorganic nitrogen, organic phosphorus, three fluorescent DOM components, nitrogen-containing molecules and carbohydrates. These results provide insights into the main drivers of marine DOM fate: at similar DOC concentrations and low inorganic P concentrations. We evience the preferential consumption of lignin-like compounds where theoretically more labile molecules were available, thus reinforcing the need of in depth molecular studies for a better understanding of DOM-microbes interactions in the ocean.

ecology↗