Welcome to IMC 2018 International Mycological Congress
Conference Calendar

 

Displaying One Session

Symposia
Location
202A 2nd Floor
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Symposia

Hot, Cold, or Salty? Comparative genomics of halophilles from hot and cold deserts.

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-1
Authors
  • J. Stajich
  • C. Coleine
  • T. Kurbessoian
  • S. Masonjones
  • C. Gostinčar
  • L. Selbmann
Symposia

Fungi in human-made water-environments

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-2
Authors
  • A. Van Diepeningen

Abstract

Abstract

It is surprising how little we know about the fungal microbiome of human-made water environments that include for instance our drinking water systems and swimming pools. Cleaning regimes and for instance chlorination levels are especially directed at bacterial contaminations. For drinking water just one country has rules for maximum levels of fungal contamination, but this is only tested when the water has a dark or brown color or smells wrong.

In this presentation both densities of fungal contaminations and species composition in the fungal populations of different human-made water-environments in the Netherlands are studied and compared to studies done in other countries. In general, fungal density and diversity are assessed based on colonies isolated using different (semi) selective media and culturing conditions and fungal identification based on molecular characterization of barcoding regions like the ITS region.

For drinking water both surface water and groundwater can be used, each resulting in a different signature of present species, but generally in low numbers. Season has an impact on observed numbers and species. Besides the observation of generalist fungal species also water- specific lineages are observed, that include low numbers of opportunistic (black) fungal species. However, especially in chlorinated pool water –probably after human contact – numbers of opportunistic pathogens dramatically increase. Some rarely observed pathogenic species prove be common inhabitants of these chlorinated pools.

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Symposia

Bass Becking was right: Polar fungi in refrigerators, tropical in dishwashers

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-3
Authors
  • P. Zalar
  • J. ZupanČiČ
  • M. Novak Babič
  • C. Gostinčar
  • L. Perini
  • N. Gunde Cimerman

Abstract

Abstract

People in developed countries spend most of their time indoors, either in their homes or at work. They are thus exposed to a variety of microorganisms that can survive selectively in indoor environments despite of applied hygiene measures and sanitation procedures. Household appliances running at high or low temperatures and with detergents accommodate selective conditions leading to the enumeration of microorganisms that are specifically adapted to these conditions. Indoor mycobiota comprises either air-borne, mostly filamentous fungi inhabiting surfaces of walls and household appliances, or water-born yeasts or filamentous fungi in tap water or bathroom, kitchen and other household appliances, like dishwashers, washing machines and refrigerators. Recent studies of wet and hot indoor niches using culturable and unculturable approaches, have revealed the occurrence of a diversity of yeast species from the genera Debaryomyces, Meyerozyma, Pichia, Saccharomyces and Yarrowia, as well as opportunistic pathogenic yeast species from genera Candida, Naganishia and Rhodotorula, and the black yeast Aureobasidium and Exophiala. From cold household devices, used to preserve food, like refrigerators and freezers, also an array of other fungi was found, many of them being food unrelated and being often detected in Arctic environments. Prevailing filamentous fungi are from genera Cladosporium, Penicillium, Aspergillus, Exophiala and Aureobasidium, while yeasts belonged to genera Candida, Debaryomyces, Naganishia, Cryptococcus, Vishniacozyma and Dioszegia. The main characteristics enabling all these fungi to colonize specified domestic environments include production of extracellular polysaccharides, ability to grow on cleaning agents, tolerance to high or low temperatures, high salt concentrations, and alkaline pH. These selected and enriched species can form surface biofilms, and can become causal agents of infections. The way of entry of all these fungi to indoor environments are via air and water. Drinking water, which is typically not accredited for fungi, often contains propaguels of opportunistic human pathogens that can cause (sub)cutaneous and catheter-related infections and infections of respiratory and urinary tract. They belong to genera such as Exophiala, Rhinocladiella, Candida and Rhodotorula. The species diversity from all above listed indoor environment is described on the basis of advanced culture dependent and DNA-based NGS techniques.

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Symposia

Lichen symbioses as a niche for extremotolerant fungi

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-4
Authors
  • M. Grube
  • F. Fernandez-Mendoza
  • E. Banchi
  • L. Muggia

Abstract

Abstract

Fungi living on lichens (lichenicolous fungi) have since long been studied but there is still little comparative information about their unseen diversity. We studied the whole diversity of lichen-associated fungi using a metabarcoding analysis of the internal-transcribed-spacer regions (ITS). We collected thalli with and without infections of specific lichenicolous fungi. The majority of the detected OTUs represented fungi of the two classes Dothideomycetes and Eurotiomycetes. Many of the fungi are also known form other niches and included rock-inhabitant and extremotolerant lineages. We assigned some of the sequences to morphologically characterized lichenicolous fungi and also assessed their potential asymptomatic presence in lichen thalli. Shared fungal composition in the thalli varied among different lichen species and did not correlate with externally visible fungal infections. In fact, microscopic data, culture-based approaches, and high throughput sequencing revealed discordant pictures of mycobiome diversity. Moreover, we find variation in diversity estimates depending on the primers used, with particular biases in the detection of Basidiomycota. Preliminary co-culture experiments reveal a potential of some extremotolerant lichen-inhabiting fungi to form interactions with the algal partner of the host.

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Symposia

Subterranean Fungi: Diversity within the Soudan Iron Mine in Northern Minnesota

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-5
Authors
  • B. Held
  • C. Salomon
  • R. Blanchette

Abstract

Abstract

Mines and caves are unusual biomes containing unique fungi and are greatly understudied compared to other environments. These studies focus on the Soudan Mine in Tower, MN, an iron ore mine that closed in 1963 after operating for 80 years. The mine has 27 levels and is 714 m deep. Although mines can be nutrient poor, there are areas in the Soudan mine with large quantities of wooden timbers. This wood was used during the mining operations and now serves as carbon source for fungi and other microorganisms. We sampled the mine to explore fungal diversity with the goal to investigate taxa that tolerate heavy metals for potential bioprocessing technologies as well as bioactive molecules for drug discovery and possible biocontrol for white nose syndrome (WNS) of bats. Fungi were cultured from samples and the ITS region was sequenced for identification and phylogenetic analysis. Results show Ascomycota are the dominating fungi followed by Basidiomycota and Mucoromycota. Out of 175 identified taxa 124 belong to the Ascomycota and 26 and 25 to Basidiomycota and Mucoromycota, respectively. There are also 49 taxa that do not match well (<97% BLAST GenBank identity) with described fungal species. Examples of the most commonly isolated fungi are: Ascomycota: Scytalidium sp., Mariannaea comptospora, Hypocrea pachybasidioides, Oidiodendron griseum and Pochonia bulbillosa; Basidiomycota: Postia sp., Sistotrema brinkmannii, Calocera sp., Amylocorticiellum sp.; Mucoromycota: Mortierella parvispora, M. gamsii, M. hyaline, M. basiparvispora and Mortierella sp. llumina high throughput sequencing was also used on samples of wood from several levels of the mine and showed that Ascomycota was dominant, including a sample with high copper concentrations. A phylogenetic analysis of identified Pseudogymnoascus sp. from the mine shows that they are closely related to P. destructans (the causal agent for WNS). Culture studies indicate they are present over extensive areas in the mine. Rhizomorphs of Armillaria sinapina were also found throughout the mine. The mine environment, with the presence of high levels of heavy metals, complete darkness and nutrient poor areas, is an extreme environment for fungi. One Ascomycota, Cadophora sp., and two Basidiomycota, Amyloathelia sp. and Jaapia argillacea, discovered in the mine are similar to genera isolated by the authors in other extreme environments. However, phylogenetic analysis shows differences in species between these environments. Many of the mine fungi have heavy metal tolerance, others show possible use for biological control of WNS. Cadophora sp. was also found to produce new compounds named soudanones. Results indicate this subterranean environment hosts unusually diverse fungi, many of them not found in above ground environments.

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Symposia

Hidden depths: Fungi in permafrost soils and a test of the paleosymbiosis hypothesis in high latitude boreal forests

Session Number
S27
Location
202A 2nd Floor, Puerto Rico Convention Center, San Juan, Puerto Rico
Date
07/20/2018
Time
08:30 AM - 10:30 AM
Presentation Number
S27-6
Authors
  • N. Day
  • C. Dieleman
  • G. Thorn
  • K. Dunfield
  • M. Turetsky
  • J. Baltzer

Abstract

Abstract

Fungi are fundamental for driving ecosystem processes of carbon and nutrient cycling, and are particularly important in carbon-rich boreal forests. Studies have demonstrated strong vertical stratification of mycorrhizal and saprotrophic communities in boreal forest soils and permafrost. Although much of the subarctic boreal forest is underlain by permafrost (ground perennially below 0°C), changing climate and increased wildfire activity has led to concerns about permafrost thaw and subsequent impacts on nutrient cycles, carbon emissions, and forest regeneration; processes in which fungi play central roles. In addition, the recently posited paleosymbiosis hypothesis suggests that there may be viable propagules in deep soils that could form effective mutualisms. These propagules could become important in boreal forests with projected drought, requiring deeper penetration of plant roots or repeated extreme wildfire events exposing mycorrhizas in deep soil layers. Northwestern North America is disproportionately impacted by climate change so gaining information on fungal taxa in soil layers can help us understand how ecosystems may function in the future. Our aim is to understand the function of fungi in different soil layers of boreal forest soils across regions. Our first objective is to describe fungal communities at different depths of boreal forest soils, including permafrost, and relate them to biogeochemical cycles (N, C) during permafrost thaw from sites with different fire histories in the Northwest Territories, Canada, and Alaska, USA. Our second objective is to test the paleosymbiosis hypothesis by determining the presence of viable ectomycorrhizal propagules from different depths and assessing their colonisation and growth impacts on seedlings. We collected 12 soil cores from active layer to deep permafrost soils from spatially distributed locations with different fire histories throughout subarctic boreal forests in our study region. Preliminary analyses of surface soils showed that fungal community structure was related to soil moisture, suggesting that changes in soil moisture due to permafrost thaw and/or climate change could have large impacts on fungal communities and subsequent biogeochemical cycling. We will present results on fungal community structure from Illumina sequencing of the active, permafrost, and deep permafrost layers. We will also present results from growth chamber experiments inoculating tree seedlings with soil from each depth to identify viable ectomycorrhizal propagules. Our study provides information on how the initial structure of fungal communities impacts C and N cycling in thawing permafrost soils, and survivability of ectomycorrhizal propagules from in deep soil layers.

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