Phylogenetic diversity and antimicrobial activities of bryozoan-associated bacteria isolated from Mediterranean and Baltic Sea habitats.
To date, only a small number of investigations covering microbe-bryozoa associations have been carried out. Most of them have focused on a few bryozoan species and none have covered the antibacterial activities of associated bacteria. In the current study, the proportion and phylogenetic classification of Bryozoan-associated bacteria with antimicrobial properties were investigated. Twenty-one specimens of 14 different bryozoan species were collected from several sites in the Baltic and the Mediterranean Sea. A total of 340 associated bacteria were isolated, and 101 displayed antibiotic activities. While antibiosis was predominantly directed against Gram-positive test strains, 16S rRNA gene sequencing revealed affiliation of the isolates to Gram-negative classes (Flavobacteria, Alpha- and Gammaproteobacteria). One isolate was related to the Gram-positive Actinobacteria. The sequences were grouped into 27 phylotypes on the basis of similarity values >or=99.5%. A host-specific affiliation was not revealed as members of the same phylotype were derived from different bryozoan species. Site-specific patterns, however, were demonstrated. Strains of the genera Sphingomonas and Alteromonas were exclusively isolated from Mediterranean sites, whereas Shewanella, Marinomonas and Vibrio-related isolates were only from Baltic sites. Although Pseudoalteromonas affiliated strains were found in both habitats, they were separated into respective phylotypes. Isolates with 16S rDNA similarity values <98%, which could possibly represent new species, belonged to the genera Shewanella, Pseudoalteromonas and Tenacibaculum.
Kieler Wirkstoff-Zentrum (KiWiZ) at the Leibniz Institute of Marine Sciences (IFM-GEOMAR), Kiel, Germany.
Herwig
H
Heindl
Jutta
J
Wiese
Vera
V
Thiel
Johannes F
JF
Imhoff
D000818:Animals; D000898:Antibiosis; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D018407:Bacterial Physiological Phenomena; D001454:Baltic States; D044822:Biodiversity; D002013:Bryozoa / Q000382:microbiology*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005843:Geography; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S