"Candidatus Sonnebornia yantaiensis", a member of candidate division OD1, as intracellular bacteria of the ciliated protist Paramecium bursaria (Ciliophora, Oligohymenophorea).
An intracellular bacterium was discovered in an isolate of Paramecium bursaria from a freshwater pond in Yantai, China. The bacteria were abundant and exclusively found in the cytoplasm of the host which, along with the green alga Chlorella, formed a three-partner consortium that could survive in pure water for at least one week. Cloning, sequencing and phylogenetic analysis of the bacterial 16S rRNA gene showed that the bacterium belonged to the uncultured candidate division OD1, which usually forms part of the rare biosphere. Transmission electron microscopy and fluorescence in situ hybridization (FISH) with specific probes showed that the bacteria were usually located close to the perialgal membranes of endosymbiotic Chlorella cells, and occasionally irregularly distributed throughout the host cytoplasm. The name "Candidatus Sonnebornia yantaiensis" gen. nov., sp. nov. is proposed for the new bacterium. A strongly supported monophyletic subclade, OD1-p, which included the new species, was recognized and this study highlights that protists can be important hosts for rare bacterial taxa.
Microbial Ecology Group, Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; College of Life Sciences, South China Normal University, Guangzhou 510631, China. Electronic address: jgong@yic.ac.cn.
Jun
J
Gong
Microbial Ecology Group, Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; College of Life Sciences, South China Normal University, Guangzhou 510631, China.
Yao
Y
Qing
Microbial Ecology Group, Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Xiaohong
X
Guo
Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom.
Alan
A
Warren
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D002681:China; D016000:Cluster Analysis; D003593:Cytoplasm / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005618:Fresh Water; D017404:In Situ Hybridization, Fluorescence; D059013:Microbial Consortia; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010247:Paramecium / Q000382:microbiology*; D010802:Phylogeny; D061005:Ponds / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
Bacterial symbiont; Digestion-resistant bacteria; Endosymbiont; FISH; OD1; OD1-p; Protozoa; Rare biosphere; SSU rRNA; Sonnebornia