Favero-Longo Sergio E, Borghi Alessandro, Tretiach Mauro, Piervittori Rosanna
Dipartimento di Biologia Vegetale-Centro di Eccellenza per la Biosensoristica Vegetale e Microbica, Università degli Studi di Torino, Viale Mattioli 25, 10125 Torino, Italy.
Mycol Res. 2009 Oct;113(Pt 10):1216-27. doi: 10.1016/j.mycres.2009.08.006. Epub 2009 Aug 14.
Sterile cultured isolates of lichen-forming aposymbionts have not yet been used to investigate lichen-rock interactions under controlled conditions. In this study mycobionts and photobiont of the endolithic lichens Bagliettoa baldensis and Bagliettoa marmorea were isolated and inoculated with coupons of one limestone and four marbles commonly employed in the Cultural Heritage framework. After one year of incubation, microscopic observations of polished cross-sections were performed to verify if the typical colonization patterns observed in the field may be reproduced in vitro and to evaluate the receptivity of the five lithotypes to endolithic lichens. The mycobionts of the two species developed both on the surface of and within all the lithotypes, showing different penetration pathways which depend on mineralogical and structural features and highlight different receptivity. By contrast, algae inoculated with the coupons did not penetrate them. Observations suggest that the hyphal penetration along intrinsic discontinuities of rocks is a relatively fast phenomenon when these organisms are generally considered as slow-growing. Samples from limestone outcrops and abandoned marble quarries, colonized by the same species or other representatives of Verrucariaceae, showed penetration pathways intriguingly similar to those reproduced in vitro and highlighted that lichen-driven erosion processes only increase the availability of hyphal passageways after a long-term colonization. These results show that in vitro incubation of sterile cultured lichen-forming ascomycetes with rock coupons is a practicable experimental system to investigate the lichen-rock interactions under controlled conditions and, together with analysis in situ, may support decisions on conservative treatments of historical and cultural significant stone substrata.
尚未使用无菌培养的地衣共生体分离物来研究在可控条件下地衣与岩石的相互作用。在本研究中，分离了内生地衣巴氏巴格衣和大理石巴格衣的真菌共生体和光合生物，并将其接种到文化遗产框架中常用的一种石灰石和四种大理石试片上。经过一年的培养，对抛光横截面进行显微镜观察，以验证在野外观察到的典型定殖模式是否可以在体外重现，并评估这五种岩石类型对内生地衣的接受性。这两个物种的真菌共生体在所有岩石类型的表面和内部都有生长，显示出不同的穿透途径，这些途径取决于矿物学和结构特征，并突出了不同的接受性。相比之下，接种到试片上的藻类没有穿透它们。观察结果表明，当这些生物通常被认为生长缓慢时，菌丝沿着岩石固有不连续处的穿透是一个相对较快的现象。来自石灰岩露头和废弃大理石采石场的样本，被疣衣科的相同物种或其他代表定殖，显示出与体外重现的穿透途径惊人地相似，并突出表明，地衣驱动的侵蚀过程只有在长期定殖后才会增加菌丝通道的可用性。这些结果表明，将无菌培养的形成地衣的子囊菌与岩石试片进行体外培养是一种可行的实验系统，用于在可控条件下研究地衣与岩石的相互作用，并且与原位分析一起，可以为具有历史和文化意义的石材基底的保护处理决策提供支持。
