Impact of golden mussel (Limnoperna fortunei) colonization on bacterial communities and potential risk to water quality

Abstract

Mussel colonization can affect the water quality through restructuring nearby bacterial communities. In this study, we conducted an experiment to detect the bacterial alteration associated with live and dead golden mussel colonies, and used a high-throughput sequencing method based on 16S rRNA genes to reveal the changes in bacterial communities. It is revealed that these bacterial assemblages consumed nutrients and/or tissues of the mussels and produced metabolites, resulting in poor water quality and low bacterial alpha-diversities, particularly in dead mussel groups. The dissimilarity of bacterial community among the live and dead mussel groups was more significant than that among the different initial water qualities, indicating that mussel colonization and living status dominates the bacterial community. Co-occurrence network analysis revealed that the bacterial community associated with live mussel colonies exhibited more intensive interactions compared to that associated with dead ones. Furthermore, phenotype prediction indicated that mussel colonies, especially the dead mussel colonies, promoted the growth of pathogenic bacteria. Amino acid metabolism and carbohydrate metabolism were dominant pathways relevant to metabolism, leading to off-odors and the production of toxic compounds. The effect of these processes on water quality suggests that mussels that might be killed in water diversion projects should be removed promptly to avoid impacts on water quality.