Diversity of aquatic pseudomonas species and their activity against the fish pathogenic oomycete Saprolegnia

TitleDiversity of aquatic pseudomonas species and their activity against the fish pathogenic oomycete Saprolegnia
Publication TypeJournal Article
Year of Publication2015
AuthorsLiu Y.Y, Rzeszutek E., van der Voort M., Wu C.H, Thoen E., Skaar I., Bulone V., Dorrestein PC, Raaijmakers J.M, de Bruijn I.
JournalPlos One
Volume10
Date Published2015/08
Type of ArticleArticle
ISBN Number1932-6203
Accession NumberWOS:000360299100065
Keywordsaquaculture; bacteria; biosynthesis; chytridiomycosis; cyclic lipopeptide surfactants; fluorescens; infections; media; parasitica; strain a199
Abstract

Emerging fungal and oomycete pathogens are increasingly threatening animals and plants globally. Amongst oomycetes, Saprolegnia species adversely affect wild and cultivated populations of amphibians and fish, leading to substantial reductions in biodiversity and food productivity. With the ban of several chemical control measures, new sustainable methods are needed to mitigate Saprolegnia infections in aquaculture. Here, PhyloChip-based community analyses showed that the Pseudomonadales, particularly Pseudomonas species, represent one of the largest bacterial orders associated with salmon eggs from a commercial hatchery. Among the Pseudomonas species isolated from salmon eggs, significantly more biosurfactant producers were retrieved from healthy salmon eggs than from Saprolegnia-infected eggs. Subsequent in vivo activity bioassays showed that Pseudomonas isolate H6 significantly reduced salmon egg mortality caused by Saprolegnia diclina. Live colony mass spectrometry showed that strain H6 produces a viscosin-like lipopeptide surfactant. This biosurfactant inhibited growth of Saprolegnia in vitro, but no significant protection of salmon eggs against Saprolegniosis was observed. These results indicate that live inocula of aquatic Pseudomonas strains, instead of their bioactive compound, can provide new (micro) biological and sustainable means to mitigate oomycete diseases in aquaculture.

DOI10.1371/journal.pone.0136241
Student Publication: 
No