BiologybioRxiv

Ranked by formulaVerdict: Notable

Unlocking Targeted Underwater Delivery of Coral Probiotics

The rapid global decline of coral reefs has intensified the need for innovative conservation strategies, including microbial therapies to enhance coral health and resilience.

By Facchinelli, Contardi, Caldwell +16

Score████░░░░░░4.3

Key numbers

  • 11.5 % after 48 h with
  • 12.7 % after 48 h with
  • 12.6 % after 24 h with

Caveats

  • Preprint; not yet peer reviewed.

VerdictWorth a reader's time today.

Read the originalPDF

Abstract

The rapid global decline of coral reefs has intensified the need for innovative conservation strategies, including microbial therapies to enhance coral health and resilience. A major limitation, however, is the lack of effective delivery systems for administering Beneficial Microorganisms for Corals (BMCs). In this study, we present natural, biodegradable systems for the underwater delivery of probiotic bacteria to corals. Three customized alginate-based delivery formats (beads, hydrogels, and filaments) were developed and loaded with the probiotic Pseudoalteromonas peptidolytica. The materials were loaded with the bacterium at an average concentration of 10^(4) CFU/g of dry polymer and engineered to sink underwater while keeping their structural integrity over time. In vitro assays showed controlled release kinetics, with encapsulated probiotics remaining viable and capable of replication. In vivo experiments compared syringe-based inoculation with the application of alginate beads, hydrogels, and filaments to corals. Microbiome analyses performed before and after inoculation confirmed successful probiotic colonization following deployment of the alginate-based delivery systems. Relative abundance of the probiotic genus Pseudoalteromonas increased markedly in treated corals, reaching 11.5 % after 48 h with alginate beads, 12.7 % after 48 h with hydrogels, and 12.6 % after 24 h with filaments. Furthermore, the degradation mechanisms of the three delivery systems were investigated. As the first biomaterial-based underwater delivery systems specifically engineered for coral probiotics, these alginate-based materials provide a promising foundation for advancing microbial therapies in both controlled aquaria and natural reef environments.

M. P. Facchinelli, M. Contardi, J. Caldwell, F. Fiorentini, I. Ghizzi, V. Calabretta, L. Ceseracciu, T. Pomili, V. Isa, G. Corigliano, C. Rinaldi, V. Scribano, E. Bellini, L. Ravelli, S. Lavorano, I. Gandolfi, P. Galli, S. Montano, A. Athanassiou

The editor's rubric

Heuristic review

Leverage3 / 5
A method or resource many groups across the field will adopt within a year.
24% of this desk’s rubric
Magnitude3 / 5
Large gain: roughly 2x, or a clear new state of the art on a hard, unsaturated problem.
16% of this desk’s rubric
Evidence3 / 5
Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
20% of this desk’s rubric
Novelty2 / 5
A new combination of known ideas.
20% of this desk’s rubric
Trajectory2 / 5
Some room to improve with obvious engineering.
10% of this desk’s rubric
Stakes3 / 5
Meaningful benefit to many people within a few years.
10% of this desk’s rubric

Editor’s rationale

Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we propose); breadth (many tasks); gains (relative gain); verification (experimental validation, independent replication); stakes (global scale, prevention or cure). Red flags: derivative (we apply).

How the score was computed

rank-2026-10-18

Score████░░░░░░4.3

Score = 10 × (75% × adjusted merit / 10 + 15% × attention + 10% × freshness)

Desks place stronger verdicts first, then use this score to order work within the same verdict.

Merit
5.4 / 10
Weighted rubric, evidence-gated.
Adjusted merit
4.6 / 10
Shrunk toward the desk prior by editor confidence (44%).
Attention
0%
Citations, upvotes, points, mentions.
Freshness
88%
Half-life decay since publication.

No attention signals recorded yet.

The record

  • Reviewed by heuristic-v10 on Nov 6, 2026, 05:48 UTC. Paper type: method.
  • Categories: bioengineering
  • BRIEF, No.8 in the Biology edition of November 6, 2026.