Gareis Manfred, Gottschalk Christoph
Chair of Food Safety, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich (LMU), Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany.
Mycotoxin Res. 2014 Aug;30(3):151-9. doi: 10.1007/s12550-014-0193-3. Epub 2014 Mar 12.
The formation of guttation droplets is a long-known property of various fungi. However, their composition, biological function and metabolism in fungi have hardly attracted deeper research interest. The highly toxic mould Stachybotrys (S.) chartarum chemotype S is supposed to play-amongst other factors such as endotoxins and microbial volatile organic compounds (MVOCs)-an important role in indoor air toxicity, mainly after water damage. The way of toxins becoming airborne and leading to exposure via inhalation, however, is still under discussion. We hypothesised that guttation may be a factor for exudation of toxins into the environment. Therefore, selected isolates (n = 15) of our own culture collection of Stachybotrys spp. (S. chartarum chemotype S, S. chartarum chemotype A, S. chlorohalonta) originating from various habitats were cultivated on malt extract agar for 3 weeks. All strains but one produced different amounts of guttation droplets, which were collected quantitatively and subjected to various independent analytical techniques like ELISA, effect-based bioassay (MTT cell culture test) and tandem mass spectrometry (LC-MS/MS). Actually, the toxigenic isolates (n = 5) produced highly toxic guttation droplets, which was confirmed by all methods. The concentration of macrocyclic trichothecenes, such as satratoxin G and H, ranged between the LOD and 7,160 ng/ml exudate and 280 and 4,610 ng/ml as determined by LC-MS/MS, respectively. According to our knowledge, the ability of S. chartarum to produce toxic exudates is reported for the first time, which possibly plays an important role regarding its toxic potential in indoor environments.
吐水液滴的形成是各种真菌早就为人所知的特性。然而，它们在真菌中的组成、生物学功能和代谢几乎没有引起深入的研究兴趣。剧毒霉菌炭疽菌化学型S被认为在室内空气毒性中起着重要作用，主要是在水浸之后，其他因素还包括内毒素和微生物挥发性有机化合物（MVOCs）。然而，毒素通过空气传播并导致吸入暴露的方式仍在讨论中。我们假设吐水可能是毒素向环境中渗出的一个因素。因此，从我们自己的炭疽菌属培养物保藏中心挑选了15个分离株（炭疽菌化学型S、炭疽菌化学型A、绿炭疽菌），它们来源于不同的生境，在麦芽提取物琼脂上培养3周。除一个菌株外，所有菌株都产生了不同量的吐水液滴，对这些液滴进行了定量收集，并采用了各种独立的分析技术，如酶联免疫吸附测定（ELISA）、基于效应的生物测定（MTT细胞培养试验）和串联质谱（LC-MS/MS）。实际上，产毒分离株（n = 5）产生了剧毒的吐水液滴，所有方法都证实了这一点。通过LC-MS/MS测定，大环单端孢霉烯族毒素（如satratoxin G和H）的浓度分别在检测限和渗出液7160 ng/ml之间以及280和4610 ng/ml之间。据我们所知，首次报道了炭疽菌产生有毒渗出物的能力，这可能在其对室内环境的潜在毒性方面起着重要作用。
