Department of Evolution and Biodiversity of Plants, Geobotany Section, Ruhr-University Bochum, Bochum, Germany.
Microb Ecol. 2012 Feb;63(2):295-303. doi: 10.1007/s00248-011-9923-7. Epub 2011 Aug 11.
Interactions between mushrooms, yeasts, and parasitic fungi are probably common in nature, but are rarely described. Bolete fruiting bodies are associated with a broad spectrum of microorganisms including yeasts, and they are commonly infected with filamentous mycoparasites of the genus Sepedonium (teleomorph Hypomyces). We report the isolation of 17 yeast strains from Paxillus and Xerocomus, 16 of which were obtained from the surface tissue, the primary site of Sepedonium infection. Phylogenetic analyses with the D1/D2 region of the 28S ribosomal gene and the internal transcribed spacers placed the yeasts as Rhodotorula, Rhodosporidium, and Mastigobasidium from the Pucciniomycotina, Cryptococcus, Cystofilobasidium, Holtermanniella, and Trichosporon from the Agaricomycotina, and Kluyveromyces from the Saccharomycotina including the first isolation of Rhodotorula graminis from Europe. To investigate the influence of the yeast strains on the mycoparasite and the host fungus, in vitro assays were conducted with Sepedonium chrysospermum and Paxillus involutus. Both S. chrysospermum growth inhibitory and stimulating yeast strains were detected among the isolates. The number of S. chrysospermum inhibitory yeast strains increased and the number of S. chrysospermum stimulatory yeast strains decreased in the presence of P. involutus in co-cultures. Low nutrient levels in the culture medium also led to an increased number of S. chrysospermum inhibitory yeast strains and ten yeasts inhibited the mycoparasite in spatial separation by a crosswall. Six yeast strains inhibited P. involutus in dual culture, and the inhibitory P. involutus yeast interactions increased to nine in the presence of S. chrysospermum. Our results suggest that the bolete-associated yeasts influence the growth of the mycoparasitic fungus, which may affect the health of the fruiting bodies.
蘑菇、酵母和寄生真菌之间的相互作用在自然界中可能很常见，但很少有描述。牛肝菌的子实体与包括酵母在内的广泛微生物群有关，它们通常被 Sepedonium 属（Hypomyces 的有性型）的丝状真菌寄生。我们从 Paxillus 和 Xerocomus 中分离出 17 株酵母菌株，其中 16 株来自 Sepedonium 感染的表面组织，这是 Sepedonium 感染的主要部位。通过 D1/D2 区的 28S 核糖体基因和内部转录间隔区的系统发育分析，将酵母鉴定为 Pucciniomycotina 的红酵母属、红冬孢酵母属和 Mastigobasidium 属、Agaricomycotina 的隐球酵母属、Cystofilobasidium 属、Holtermanniella 属和 Trichosporon 属以及 Saccharomycotina 的克鲁维酵母属，其中包括首次从欧洲分离出的 Rhodotorula graminis。为了研究酵母菌株对真菌寄生物和宿主真菌的影响，我们进行了 Sepedonium chrysospermum 和 Paxillus involutus 的体外测定。在分离株中检测到对 S. chrysospermum 生长有抑制和刺激作用的酵母菌株。在共培养中，当存在 P. involutus 时，抑制 S. chrysospermum 的酵母菌株数量增加，而刺激 S. chrysospermum 的酵母菌株数量减少。培养基中低营养水平也导致抑制 S. chrysospermum 的酵母菌株数量增加，10 株酵母通过隔壁在空间上分离抑制真菌寄生物。在双培养中，有 6 株酵母抑制 P. involutus，而在存在 S. chrysospermum 的情况下，抑制 P. involutus 的酵母相互作用增加到 9 个。我们的结果表明，牛肝菌相关的酵母会影响真菌寄生物的生长，这可能会影响子实体的健康。
