These were AcM9, AcM11, AcM20, AcM29 and AcM30. m/z?=?1006.5 at [MS-H]-). 1471-2180-12-164-S2.pdf (40K) GUID:?A4A6EE1F-6D56-4A31-A094-5EB2E8C1F63A Additional file 3 sp. AcM11 produces a derivative of Acta 2930-B1 Comparisons between the chromatogram and the averaged masses of the ions from Acta 2930-B1 real material and from peak IV of AcM11 extract, prepared as described in Methods. (a) The chromatogram of Acta 2930-B1 real 1alpha-Hydroxy VD4 substance (blue) and the AcM11 extract (red). Average masses of Acta 2930-B1 real substance and the AcM11 extract are in ESI-MS positive (b, d) and unfavorable (c, e) modes. Note 1alpha-Hydroxy VD4 that the dominant masses in peak IV deviate one m/z unit from the respective values of the Acta 2930-B1 real material. 1471-2180-12-164-S3.pdf (20K) GUID:?9A4D51DD-1A3B-4C25-A555-8F7F1D92253B Additional file 4 Antifungal influence of AcM11 and cycloheximide was tested in a Petri dish bioassay test against 331 and 005. (a, d) Influence of AcM11 around the growth of the fungus. AcM11 was applied on agar medium and the fungus was inoculated. The front of the fungal colony was circled by pencil. (b, e) Influence of cycloheximide on fungal growth. Methanol or in methanol dissolved cycloheximide was applied by filter paper on the top of the agar medium. Note that growth under the influence of 4?nmol cycloheximide is comparable to growth with 50?nmol cycloheximide. The front of the fungal colony was circled by pencil. (c, f) Influence of cycloheximide on fungal Rabbit Polyclonal to TRXR2 growth on fungal growth. Extension of fungal mycelium was measured after one week of growth on cycloheximide made up of medium (n?=?9). Cycloheximide concentration range in the bioassay is based on the observed production level in the AcM11 suspension culture, which was 10.2?nmol x ml-1. Note the lower levels of cycloheximide applications to than to Actinobacteria, known as antibiotic suppliers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly species as the fungal partner. Results Fifteen isolates exhibited substantial variation in inhibition of tested mycorrhizal and herb pathogenic fungi (was stimulated by some of the streptomycetes, and was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The decided patterns of strains, which are not general antagonists of fungi, may produce still un-described metabolites. Background Herb growth is usually influenced by the presence of bacteria and fungi, and their interactions are particularly common in the rhizospheres of plants with high relative densities of microbes [1]. Pro- and eukaryotic microorganisms compete for simple plant-derived substrates and have thus developed antagonistic strategies. Bacteria have found niches with respect to the utilization of fungal-derived substrates as well, with their nutritional strategies ranging from hyphal exudate consumption to endosymbiosis and mycophagy [2,3]. Current applications related to bacterial-fungal interactions include biocontrol of fungal herb diseases [4] and controlled stimulation of mycorrhizal contamination [5]. Better insight into the co-existence mechanisms of soil bacteria and fungi is crucial in order to improve existing applications and to invent new ones. Abundant in the rhizospheres of plants, the streptomycetes are best known for their capacity to control herb diseases (reviewed by [6,7]). The fact that many streptomycetes are able to produce antifungal compounds indicates that they may be competitors of fungi. Direct inhibition of fungal parasites may lead to herb protection and is often based on antifungal secondary metabolites [8,9]. In parallel to antibiotics, the streptomycetes produce a repertoire of other small molecules, including for instance root growth-inducing auxins [10] and iron acquisition-facilitating siderophores [11]. Ectomycorrhiza formation between filamentous fungi and forest tree roots is crucial to satisfying the nutritional requires of forest trees [12]. The ectomycorrhizas (EM) 1alpha-Hydroxy VD4 and the symbiotic fungal mycelia, the mycorrhizosphere, are associated with diverse bacterial communities. Until now, studies around the functional significance of EM associated bacteria have been rare [13-15]. Nevertheless, diverse roles have been implicated for these bacteria, including stimulation of EM formation, improved nutrient acquisition and participation in herb protection (reviewed in [5]). An important question to be resolved with EM associated bacteria is whether there is a specific selection for particular bacterial strains by mycorrhizas, since this would indicate an established association between the bacteria, the EM fungus, and/or the herb root. Frey-Klett et al. [13] observed such interdependency: the community of fluorescent pseudomonads from EM with the fungus was more antagonistic.