title: Molecular and chemical dialogues in bacteria-protozoa interactions.
abstract: Protozoan predation of bacteria can significantly affect soil microbial community composition and ecosystem functioning. Bacteria possess diverse defense strategies to resist or evade protozoan predation. For soil-dwelling Pseudomonas species, several secondary metabolites were proposed to provide protection against different protozoan genera. By combining whole-genome transcriptome analyses with (live) imaging mass spectrometry (IMS), we observed multiple changes in the molecular and chemical dialogues between Pseudomonas fluorescens and the protist Naegleria americana. Lipopeptide (LP) biosynthesis was induced in Pseudomonas upon protozoan grazing and LP accumulation transitioned from homogeneous distributions across bacterial colonies to site-specific accumulation at the bacteria-protist interface. Also putrescine biosynthesis was upregulated in P. fluorescens upon predation. We demonstrated that putrescine induces protozoan trophozoite encystment and adversely affects cyst viability. This multifaceted study provides new insights in common and strain-specific responses in bacteria-protozoa interactions, including responses that contribute to bacterial survival in highly competitive soil and rhizosphere environments.
authors.affiliation: 1] Laboratory of Phytopathology, Wageningen University, 6708 PB Wageningen, the Netherlands [2] Microbial Ecology Department, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands.
authors.forename: Chunxu
authors.initials: C
authors.lastname: Song
authors.affiliation: USDA-ARS, 1104 N. Western Ave., Wenatchee, Washington 98801.
authors.forename: Mark
authors.initials: M
authors.lastname: Mazzola
authors.affiliation: Laboratory of Phytopathology, Wageningen University, 6708 PB Wageningen, the Netherlands.
authors.forename: Xu
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Center for Industrial Mathematics, University of Bremen, 28359 Bremen, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Oetjen
authors.affiliation: 1] MALDI Imaging Lab, University of Bremen, 28359 Bremen, Germany [2] Center for Industrial Mathematics, University of Bremen, 28359 Bremen, Germany [3] SCiLS GmbH, 28359 Bremen, Germany [4] Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego , San Diego, California 92093, United States [5] Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
authors.forename: Theodore
authors.initials: T
authors.lastname: Alexandrov
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego , San Diego, California 92093, United States.
authors.forename: Pieter
authors.initials: P
authors.lastname: Dorrestein
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego , San Diego, California 92093, United States.
authors.forename: Jeramie
authors.initials: J
authors.lastname: Watrous
authors.affiliation: Laboratory of Phytopathology, Wageningen University, 6708 PB Wageningen, the Netherlands.
authors.forename: Menno
authors.initials: M
authors.lastname: van der Voort
authors.affiliation: 1] Laboratory of Phytopathology, Wageningen University, 6708 PB Wageningen, the Netherlands [2] Microbial Ecology Department, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands.
authors.forename: Jos M
authors.initials: JM
authors.lastname: Raaijmakers
mesh_terms: D055666:Lipopeptides / Q000235:genetics / Q000378:metabolism; D009253:Naegleria / Q000235:genetics* / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D059467:Transcriptome / Q000502:physiology
chemical_list: D055666:Lipopeptides; D011700:Putrescine