title: Diversity of Aquatic Pseudomonas Species and Their Activity against the Fish Pathogenic Oomycete Saprolegnia.
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.
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands.
authors: Yiying
authors: Y
authors: Liu
authors: Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors: Elzbieta
authors: E
authors: Rzeszutek
authors: Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands.
authors: Menno
authors: M
authors: van der Voort
authors: Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America; Department of Chemistry, Boston University, Boston, United States of America.
authors: Cheng-Hsuan
authors: CH
authors: Wu
authors: Norwegian Veterinary Institute, Oslo, Norway; Norwegian University of Life Sciences, Oslo, Norway.
authors: Even
authors: E
authors: Thoen
authors: Norwegian Veterinary Institute, Oslo, Norway.
authors: Ida
authors: I
authors: Skaar
authors: Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors: Vincent
authors: V
authors: Bulone
authors: Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America; Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America; Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America.
authors: Pieter C
authors: PC
authors: Dorrestein
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
authors: Jos M
authors: JM
authors: Raaijmakers
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
authors: Irene
authors: I
authors: de Bruijn
mesh_terms: D000818:Animals; D001483:Base Sequence; D044822:Biodiversity; D004531:Eggs / Q000382:microbiology; D005393:Fish Diseases / Q000382:microbiology; D007239:Infections / Q000382:microbiology; D008969:Molecular Sequence Data; D011549:Pseudomonas / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D012474:Salmon / Q000382:microbiology; D044762:Saprolegnia / Q000382:microbiology*; D014871:Water Microbiology