title: Oxalic acid: a signal molecule for fungus-feeding bacteria of the genus Collimonas?
abstract: Mycophagous (=fungus feeding) soil bacteria of the genus Collimonas have been shown to colonize and grow on hyphae of different fungal hosts as the only source of energy and carbon. The ability to exploit fungal nutrient resources might require a strategy for collimonads to sense fungi in the soil matrix. Oxalic acid is ubiquitously secreted by soil fungi, serving different purposes. In this study, we investigated the possibility that collimonads might use oxalic acid secretion to localize a fungal host and move towards it. We first confirmed earlier indications that collimonads have a very limited ability to use oxalic acid as growth substrate. In a second step, with using different assays, we show that oxalic acid triggers bacterial movement in such a way that accumulation of cells can be expected at micro-sites with high free oxalic acid concentrations. Based on these observations we propose that oxalic acid functions as a signal molecule to guide collimonads to hyphal tips, the mycelial zones that are most sensitive for mycophagous bacterial attack.
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, 6708 PB, The Netherlands.|Department of Plant Health, Institute for Vegetable and Ornamental Crops, Großbeeren/Erfurt e.V., Theodor Echtermeyer Weg 1, D-14979, Großbeeren, Germany.
authors: M B
authors: MB
authors: Rudnick
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, 6708 PB, The Netherlands.|Institute of Biology, Leiden University, Leiden, 2333 BE, The Netherlands.
authors: J A
authors: JA
authors: van Veen
authors: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, 6708 PB, The Netherlands.|Department of Soil Quality, Wageningen University, Wageningen, 6708 PB, The Netherlands.
authors: W
authors: W
authors: de Boer
mesh_terms: D002244:Carbon / Q000378:metabolism; D004734:Energy Metabolism; D005658:Fungi / Q000378:metabolism*; D008124:Locomotion; D056265:Microbial Interactions; D019815:Oxalic Acid / Q000378:metabolism*; D042802:Oxalobacteraceae / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology; D015398:Signal Transduction
chemical_list: D002244:Carbon; D019815:Oxalic Acid