Katrina Sandona 1, Zachary Gossage 1, and Andrea Porras-Alfaro 1,2, Donald Natvig 2, Miriam...

Katrina Sandona1, Zachary Gossage1, and Andrea Porras-Alfaro1,2, Donald Natvig2 , Miriam Hutchinson2 and Amy Powell3

1. Department of Biology, Western Illinois University, 2. University of New Mexico, 3. Sandia National Laboratory

Thermophilic Fungi in Biological Soil Crust at the Sevilleta LTER

Introduction:• Biological soil crusts are a very important components of desert ecosystems. These patchy soil areas are dominated by a community of cyanobacteria (photosynthetic bacteria), lichens (association between fungi and algae) and fungi. • The fungi that are found in the soil crust form a symbiotic relationship with the plants. These fungi can increase plant’s resistance to low rainfall and increase the plant ability to obtain nutrients from the soil crust (Collins et al, 2008, Porras-Alfaro et al, 2008)• Gypsum deposits are mainly composed of calcium carbonate, these low nutrient areas are known to contain a high number of endemic plants and potential new thermophilic fungal species (i.e. fungi that grow at 50 ° C).

References: Collins, S. L., Sinsabaugh, R. L., Crenshaw, C., Green, L., Porras-Alfaro, A., Stursova, M., & Zeglin, L. H. (2008). Pulse dynamics and microbial processes in aridland ecosystems. Journal of Ecology, 96(3), 413-420. doi:10.1111/j.1365-2745.2008.01362.xPorras-Alfaro, A., Herrera, J., Sinsabaugh, R., Odenbach, K., Lowrey, T. & Natvig, D. (2008). Novel root fungal consortium associated with a dominant desert grass. Applied and Environmental Microbiology, 74(9), 2805-2813. 

All fungi isolated were true thermophiles showing that soils from arid systems have great potential as a source of thermophilic fungi

Results:

Biological Soil Crust

Methods

Plated on MEA + Antibiotics, incubated at 50°C

Isolation of Thermophiles

Pure Cultures

Molecular Analysis

Microscopy

Temperature Experiment

DNA sequencing

Objective: To isolate, identify, and describe thermophilic fungi from gypsum biological soil crust collected in New Mexico

All of the cultures at 50 ° showed growth between 0.7 and 4.7 cm after a week. The samples at room temperature did not grow. Three of the samples were identify as Thermomyces.

Isolates Sample type Isolation date Preliminary identification

SF - 20 Gypsum 10 -3 11/15/2010 Chaetomium sp.

SF - 21 Gypsum 9 - 1 11/12/2010 Chaetomium sp.

SF - 24 Gyp. EYSA 60-1 11/15/2010 Thermomyces

SF - 31 Gypsum 6 -1 11/12/2010 Thermomyces

SF - 34 Gypsum 10-2 11/12/2010 Thermomyces

Lichenized gypsum crust

Plated gypsum soil incubated at

50°C Temperature Experiment

Electrophoresis gel showing DNA amplifications from pure cultures

Fungus growing at 50° C

Fungus did not grow at 25° C

Thermophiles are fungi whose optimal growth temperature is between 45 and

50° C

Acknowledgements: This project was supported by an Undergraduate Research Award from the College of Art and Sciences, and by University of New Mexico, the Biology department at WIU, NSF-Sevilleta LTER.

Distribution of biological soil crust from NM and some endemic plant species

Isolation of thermophiles

Isolates at 50°C. A total of 8 fungi were

obtained from gypsumTrue thermophiles

Preliminary identification of thermophilic fungi

Conclusions: