Unearthing the biodiversity of the Mucoromycota fungi within the Caesarea Mediterranean Scrub and the Be’er Sheva Negev Desert in Israel
Board Location: #25
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Microbiology/Immunology/Virology
Session: 3
Edmarie Rivera Sánchez - University of Puerto Rico, Arecibo Campus
Co-Author(s): Nicole K. Reynolds, Cornell University, NY; Marcelo Sternberg, Tel Aviv University, Israel; Teresa E. Pawlowska, Cornell University, NY
The phylum Mucoromycota is a poorly understood fungal group that encompasses globally distributed species of significant ecological value. This phylum can harbor endosymbiotic bacteria (EB) within their hyphae and these relationships are still understudied. The isolation and identification of Mucoromycota species and their EB present in these soils helps improve understanding of the biodiversity of these groups, as well as provide insights into their functional symbiotic role in the ecosystem. Using soil samples from Israel’s Desert and Xeric Shrubland and Mediterranean Scrub biomes, the goals were: (1) survey the diversity of the subphylum Mucoromycotina fungal species present, (2) screen fungal isolates for the presence of putative EB, and (3) compare fungal/EB species composition and relationships across sites and plant hosts. It was expected that the desert site would be dominated by Rhizopus and Actinomucor species compared to the coastal site, and that the prevalence of EB would be around 10%. It was anticipated that fungal species composition will be different between both sites and plant hosts.To isolate fungi, soil samples were sprinkled onto two different media types and incubated at room temperature for several days. Fungal isolates were obtained in pure culture using sterile technique, and mycelia were harvested for DNA extraction and PCR amplification. PCR screening methods were used to amplify the 28S and ITS rDNA region of fungi and 16SrDNA genes for bacteria. A variety of fungal species were found, whose morphology and phylogenetic analysis showed they belong to the genera Actinomucor, Cunningmella, Mucor, and Rhizopus. From the 29 isolates, four yielded sequences of 16S rRNA gene indicating putative EB close to 14% of prevalence. The most recurrent fungal species was from the genus Rhizopus in the Mediterranean scrub, while in the desert the most common species was Cunninghamella. Regarding the results of the desert, this finding does not support the initial hypothesis formulated that Rhizopus would be the dominant genus in the desert. It was also clear that the Mediterranean scrub soil showed a more uniform fungal composition along a longitudinal gradient compared to the desert. Also, fungal composition was most diverse in Asteraceae plant hosts (Artemisia monosperma and Artemisia herba-alba) at the Mediterranean Scrub and Desert and Xeric Shrubland, respectively. The future research aims to understand biological, physical and chemical factors that may help explain their global distribution and confirm the presence of EB within the hyphae of the isolated species.References: Okrasińska, A., Bokus, A., Duk, K., Gęsiorska, A., Sokołowska, B., Miłobędzka, A., Wrzosek, M., & Pawłowska, J. (2021). New Endohyphal Relationships between Mucoromycota and Burkholderiaceae Representatives. Applied and environmental microbiology, 87(7), e02707-20. https://doi.org/10.1128/AEM.02707-20.
Funder Acknowledgement(s): This study was supported by the National Science Foundation for providing the grants DEB-2030338 and DBI-1852141. I’ll like to thank Microbial Friends & Foes REU program at CHIMID School in Cornell University, NY. Special thanks to my PI Dr. Teresa Pawlowska, my mentor Dr. Nicole Reynolds, Dr. Chase Mayers and all the Pawlowska Lab for their guidance and support.
Faculty Advisor: Teresa E. Pawlowska, tep8@cornell.edu
Role: As part of the REU program, I elaborated the research proposal that was then verified and approved by my advisor Dr. Pawlowska, my mentor Dr. Reynolds and the program coordinator Dr. Tory Hendry. Both hypothesis were established with my mentor since there was preliminary data that I had to take into consideration. I was trained to do laboratory techniques that included culture growth, culture isolation with sterilization techniques, DNA extraction, DNA preservation, PCR and the basics of phylogenetic map elaboration and data analysis. All this research was done in a period of 9 weeks.