The freshwater sponge Ephydatia fluviatilis harbours diverse Pseudomonas species (Gammaproteobacteria, Pseudomonadales) with broad-spectrum antimicrobial activity. | - CCMAR -

Journal Article

TitleThe freshwater sponge Ephydatia fluviatilis harbours diverse Pseudomonas species (Gammaproteobacteria, Pseudomonadales) with broad-spectrum antimicrobial activity.
Publication TypeJournal Article
AuthorsKeller-Costa, T, Jousset, A, van Overbeek, L, van Elsas, JDirk, Costa, R
Year of Publication2014
JournalPLoS One
Volume9
Issue2
Date Published2014
Paginatione88429
ISSN1932-6203
KeywordsAnimals, Antibiosis, Biofilms, Gene Expression Regulation, Bacterial, Genome, Bacterial, Genotype, Likelihood Functions, Microbial Sensitivity Tests, Multivariate Analysis, Phylogeny, Polymerase Chain Reaction, Porifera, Principal Component Analysis, Pseudomonas, RNA, Ribosomal, 16S, Species Specificity
Abstract

Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is rudimentary. We assessed the diversity, structure and antimicrobial activities of Pseudomonas spp. in the freshwater sponge Ephydatia fluviatilis. Polymerase Chain Reaction--Denaturing Gradient Gel Electrophoresis (PCR-DGGE) fingerprints of the global regulator gene gacA revealed distinct structures between sponge-associated and free-living Pseudomonas communities, unveiling previously unsuspected diversity of these assemblages in freshwater. Community structures varied across E. fluviatilis specimens, yet specific gacA phylotypes could be detected by PCR-DGGE in almost all sponge individuals sampled over two consecutive years. By means of whole-genome fingerprinting, 39 distinct genotypes were found within 90 fluorescent Pseudomonas isolates retrieved from E. fluviatilis. High frequency of in vitro antibacterial (49%), antiprotozoan (35%) and anti-oomycetal (32%) activities was found among these isolates, contrasting less-pronounced basidiomycetal (17%) and ascomycetal (8%) antagonism. Culture extracts of highly predation-resistant isolates rapidly caused complete immobility or lysis of cells of the protozoan Colpoda steinii. Isolates tentatively identified as P. jessenii, P. protegens and P. oryzihabitans showed conspicuous inhibitory traits and correspondence with dominant sponge-associated phylotypes registered by cultivation-independent analysis. Our findings suggest that E. fluviatilis hosts both transient and persistent Pseudomonas symbionts displaying antimicrobial activities of potential ecological and biotechnological value.

DOI10.1371/journal.pone.0088429
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/24533086?dopt=Abstract

Alternate JournalPLoS ONE
PubMed ID24533086
PubMed Central IDPMC3922812
CCMAR Authors