Favero-Longo Sergio Enrico, Girlanda Mariangela, Honegger Rosmarie, Fubini Bice, Piervittori Rosanna
Dipartimento di Biologia, Vegetale Centre of Excellence for Plant and Microbial Biosensing, University of Torino, Torino 10125, Italy.
Mycol Res. 2007 Apr;111(Pt 4):473-81. doi: 10.1016/j.mycres.2007.01.013. Epub 2007 Jan 26.
Sterile cultured isolates of lichen-forming ascomycetes have not yet been used to investigate mycobiont-mineral substrate interactions under controlled conditions. In this study Candelariella vitellina, Xanthoparmelia tinctina and Lecanora rupicola mycobionts were isolated and inoculated with chrysotile fibres in the laboratory, in order to verify whether physical and chemical weathering processes, which were already described in the field, may be reproduced in vitro. Tight adhesion of hyphae to chrysotile fibres was observed in all species. The adhering hyphae affected the chemical composition of asbestos fibres, with the selective depletion of magnesium being a prominent feature, as is the case in field conditions. Oxalic acid and pulvinic acid, mycobiont-derived metabolites of X. tinctina and C. vitellina, were involved in the weathering action. Time and environmental factors and the absence of biological synergisms strongly limited the chemical weathering in vitro compared with what was observed in the field. Nevertheless, the results show that in vitro incubation of sterile-cultured lichen-forming fungi with minerals is a practicable experimental system to investigate the weathering effects of different mycobionts and fungal compounds under controlled conditions.
尚未使用无菌培养的地衣形成子囊菌分离物在可控条件下研究菌共生体与矿物基质的相互作用。在本研究中，在实验室中分离出了黄斑盘菌、黄髓梅衣和石生茶渍衣的菌共生体，并接种了温石棉纤维，以验证在野外已描述的物理和化学风化过程是否可以在体外重现。在所有物种中均观察到菌丝与温石棉纤维紧密粘附。粘附的菌丝影响了石棉纤维的化学成分，镁的选择性消耗是一个突出特征，这与野外情况相同。草酸和普尔文酸是黄髓梅衣和黄斑盘菌的菌共生体衍生的代谢产物，参与了风化作用。与野外观察到的情况相比，时间、环境因素以及缺乏生物协同作用强烈限制了体外的化学风化。然而，结果表明，在可控条件下，将无菌培养的地衣形成真菌与矿物质进行体外培养是一种可行的实验系统，可用于研究不同菌共生体和真菌化合物的风化作用。
