title: Calcium is required for ixotrophy of Aureispira sp. CCB-QB1.
abstract: Ixotrophy is a process that enables certain microbes to prey on other cells. The ability of cells to aggregate or adhere is thought to be a significant initial step in ixotrophy. The gliding, multicellular filamentous bacterium Aureispira sp. CCB-QB1 belongs to the family Saprospiraceae and preys on bacteria such as Vibrio sp. in seawater. Adhesion and cell aggregation were coincident with preying and were hypothesized to play an important role in the ixotrophy in this bacterium. To test this hypothesis, experiments to elucidate the mechanisms of aggregation or adhesion in this bacterium were performed. The ability of Aureispira QB1 to adhere and aggregate to prey bacterium, Vibrio sp., required divalent cations, especially calcium ions. In the presence of calcium, Aureispira QB1 cells captured 99 % of Vibrio sp. cells after 60 min of incubation. Toluidine blue O, which binds acidic polysaccharides, bound to Aureispira QB1 and inhibited adhesion of Aureispira QB1. These results suggest that acidic polysaccharides are needed for aggregation or adhesion of Aureispira and that calcium ions play a significant role in these phenomena.
authors: Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia.
authors: Go
authors: G
authors: Furusawa
authors: Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, USA.
authors: Patricia L
authors: PL
authors: Hartzell
authors: Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia.|Centre for Drug Research, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors: Visweswaran
authors: V
authors: Navaratnam
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D041963:Bacteroidetes / Q000378:metabolism* / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D011235:Predatory Behavior; D017422:Sequence Analysis, DNA; D014733:Vibrio / Q000502:physiology
chemical_list: D002413:Cations, Divalent; D011135:Polysaccharides, Bacterial; D002118:Calcium