Department of Sciences, School D. Maria II, V. N. Famalicao, Portugal.
Drug Chem Toxicol. 2010 Jul;33(3):269-78. doi: 10.3109/01480540903431440.
Aquatic hyphomycetes are a relevant group of fungi that play a crucial role as intermediaries between plant detritus and invertebrates in clean or metal-polluted streams. In this study, we investigated the effects of Zn, Cu, Ni, and Cd on the growth and sporulation of several aquatic hyphomycete species. Effects of these metals on growth were assessed in solid and liquid media with different compositions [1% malt extract (ME) and a mineral medium supplemented with vitamins and 2% glucose (MK)], and fungal sensitivity to metals was compared. The exposure to Zn or Cd inhibited the sporulation of Heliscus submersus and Tricladium chaetocladium, with these effects being stronger in the latter species. In solid medium, mydelial growth was linear, and, in most cases, metals negatively affected fungal growth. The sensitivity of aquatic hyphomycetes to metals, assessed as the metal concentration inhibiting biomass production in 50% (EC(50)), showed that Ypsilina graminea and Varicosporium elodeae were the most resistant species to Zn, while Alatospora acuminata, H. submersus, and Flagellospora curta appeared to be the most resistant fungus to Cu. Generally, lower toxicity of Zn or Cu than Ni or Cd was found. However, EC(50) values were about 20 times higher in solid than in liquid medium. Changes in nutrient supplies to fungi affected metal toxicity, as shown by higher EC(50) values in MK than ME. Complementarily, fungal tolerance to metals varied with fungal species as well as metal type.
水生丝孢菌是一类重要的真菌，它们在清洁或重金属污染溪流中作为植物碎屑和无脊椎动物之间的中介起着至关重要的作用。在这项研究中，我们调查了 Zn、Cu、Ni 和 Cd 对几种水生丝孢菌物种生长和孢子形成的影响。在不同成分的固体和液体培养基中[1%麦芽提取物 (ME) 和添加维生素的矿物质培养基和 2%葡萄糖 (MK)]评估了这些金属对生长的影响，并比较了真菌对金属的敏感性。暴露于 Zn 或 Cd 抑制了 Heliscus submersus 和 Tricladium chaetocladium 的孢子形成，后者的影响更强。在固体培养基中，菌线生长呈线性，而且在大多数情况下，金属会对真菌生长产生负面影响。用金属浓度抑制生物量生产 50%（EC(50)）来评估水生丝孢菌对金属的敏感性，结果表明，Ypsilina graminea 和 Varicosporium elodeae 对 Zn 的抗性最强，而 Alatospora acuminata、H. submersus 和 Flagellospora curta 对 Cu 的抗性最强。通常，Zn 或 Cu 的毒性低于 Ni 或 Cd。然而，在固体培养基中的 EC(50) 值比在液体培养基中高约 20 倍。向真菌提供的营养物质的变化会影响金属的毒性，如在 MK 中的 EC(50) 值高于 ME。此外，真菌对金属的耐受性因真菌种类和金属类型而异。
