L. Selbmann

Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions.

Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency).

Phylogeny and taxonomy of meristematic rock-inhabiting black fungi in the Dothideomycetes based on multi-locus phylogenies

The last decade has revealed an unexpected fungal diversity associated with natural rocks, often collected in environments influenced by harsh climatic conditions. Yet the phylogenetic affiliations and the taxonomy of many of these extreme fungi, mainly within Dothideomycetes, the largest class of Ascomycota, have only partially been described. In the present study we confirm that most rock inhabiting-fungi (RIF) are highly polyphyletic among Dothideomycetidae, mainly within the order Capnodiales, an order otherwise incorporating several families of major plant pathological importance. Novel taxa were identified within the two major and distinct clades of Teratosphaeriaceae, both comprising meristematic black fungi. Thirty one novel species and 13 new genera are proposed, based on ITS and partial nucLSU, RPB2 and BT2 sequences.

Mountain tips as reservoirs for new rock-fungal entities: Saxomyces gen. nov. and four new species from the Alps

As part of a worldwide sampling nine black fungi were isolated from rocks collected in four distinct sites of the Alps at high altitudes. Based on a nucSSU, nucLSU and mtSSU multi-locus phylogeny, seven of them were found to cluster into a distinct and well-supported clade in a basal position within the Class Dothideomycetes. As in other rock fungi these new groups of isolates were characterized by a meristematic growth and a scarcely differentiated morphology with highly melanized and thick-walled toruloid hyphae. Nonetheless, few peculiar characters were also observed as convoluted hyphal tips and the production of spherical propagules. The new genus and species Saxomyces alpinus and S. penninicus, are here described based on morphological and molecular data, in a yet to be defined order of the Dothideomycetes. The remaining two black fungi clustered in Cryomyces, a genus previously exclusively found in rocks from the McMurdo Dry Valleys in Antarctica. These two isolates were genetically distant from other Antarctic Cryomyces species based on ITS sequences, and they showed a peculiar morphology; they are here described as the new species C. montanus and C. funiculosus. Implications of our results on the evolution, adaptation and dispersal of rock-inhabiting fungi under extreme conditions are discussed.

Extremotolerant rock inhabiting black fungi from Italian monumental sites

A wide sampling for isolating highly destructive and extremotolerant black fungi was performed from Italian monuments in selected historical sites which include the “Cortile della Pigna”, Vatican Museum and the St Peter colonnade (Vatican City State), the monumental cemetery of Bonaria (Cagliari), and other monuments in the city of Cagliari. Thirty out of seventy-four strains isolated were identified basing on ITS Blastn comparison. Based on multilocus phylogeny and morphological data, one new genus and species Lithophila guttulata, five new species Knufia marmoricola, K. vaticanii, K. karalitana, K. mediterranea and Exophiala bonariae, order Chaetothyriales and one new genus and species, Saxophila tyrrhenica, and two new species Vermiconia calcicola and Devriesia sardiniae, order Capnodiales, were proposed. Ecological considerations are put forward.

Rock-inhabiting fungi and their role in deterioration of stone monuments in the Mediterranean area

Most of the cultural heritage is in the Mediterranean area. Stone was historically the most durable and widely used building material; therefore, the greatest deal of antiques is represented by stone monuments located in outdoor environments. Atmospheric agents, pollution, and various stresses are the main causes of deterioration of artistic heritage as well as many micro-organisms that often cause irreversible damages. Conservation of this invaluable patrimony, therefore, is a demanding challenge. Rock-inhabiting fungi (RIF) are very active agents causing visible alteration patterns and exfoliation of stone monuments; ecological conditions in the Mediterranean rocks are optimal for RIF development. Along with environmental conditions, fungal colonization depends also on bioreceptivity of the surfaces and survival strategies of colonizing species. This paper represents an overview of RIF biodiversity on stone monuments known at present, mechanisms of attack and colonization and outdoor conditions allowing the settlement of RIF propagules, colonization, and the following biodeterioration processes.

Black Yeasts in Cold Habitats

Black yeasts have already been known since the end of the nineteenth century, but for a number of reasons, only few workers were familiar with them. That was since recently, until the wealth of biodiversity, stunning ecologies and potential applications have become apparent. Some remote and extreme locations, such as mountain tops, glaciers or polar areas, are now being investigated by mycologists. Many rock-colonizing fungi have been interpreted for long time as blackish fly-ash particles or dust on marble monuments or buildings. Black yeasts are easily overlooked in routine studies due to their very slow growth and poor competitive abilities. With the improvement isolation procedures, it has become clear that black yeasts are actually much more common and widespread than previously believed. Identification was hampered by their morphological plasticity, until molecular techniques became a routine approach in fungal systematic. In this chapter, the authors aim to give an overview of all the aspects concerning this unconventional group of fungi, from their peculiar ecology to their wide spectrum of biodiversity. Understanding about their ecological amplitude arose from impressive efforts in sampling remote habitats and concomitant sequencing activity during the last two decades.