Deep-sea bacteria trigger settlement and metamorphosis of the mussel Mytilus coruscus larvae

Abstract

Bacteria from coast seawaters are widely known to induce larval recruitment of many invertebrates. However, whether and how deep-sea bacteria, that play crucial roles in the ecological and biogeochemical cycles, promote larval recruitment remains little known. Here, the interaction between deep-sea bacterial biofilms (BFs) and Mytilus coruscus larvae was tested. All these nine deep-sea bacterial isolates triggered planktonic-sessile transition, and the highest percentage of post-larvae was observed in Virgibacillus sp. 1 BF. Except for Pseudomonas sp. 3, Pseudoalteromonas sp. 32 and Bacillus sp. 13, other BF cell densities were significantly related to their corresponding inductive efficiency. The deep-sea Virgibacillus sp. 1 BFʼs cue that triggers planktonic-sessile transition was uncovered. Treating Virgibacillus sp. 1 BFs through physic-chemical approaches reduced inducing impact and cell survival. The conditioned water collaborated with formalin-fixed Virgibacillus sp. 1 BF hoisted planktonic-sessile transition efficiency in comparison to each one alone. Thus, two signals derived from deep-sea bacteria trigger planktonic-sessile transition in M. coruscus. This finding firstly demonstrates that deep-sea bacteria has good potential for application in the mussel seed production and provides novel insight to clarify the bacteria-mussel interaction.

Antifouling activity of bacterial extracts associated with soft coral and macroalgae from the Red Sea

“…After the growth of the biofilm bacteria, they adhere to the surface and colonise it to form biofilm. Bacteria are the initial colonisers on any newly exposed surface in marine waters, and they have been shown to influence the settlement of larval invertebrates (Hadfield 2010;Antunes et al 2019;Dobretsov & Rittschof 2020;Peng et al 2020;Chang et al 2021). As a result, the adhesion assay utilising bacteria isolated from biofilms could be useful in developing natural products into antifouling agents.…”