The Collection of Zoosporic Eufungi at the University of Michigan (CZEUM): A New Resource Unifying Historically Significant Research Collections

The Collection of Zoosporic Eufungi at the University of Michigan (CZEUM): A New Resource Unifying Historically Significant Research Collections

By D. Rabern Simmons and Timothy Y. James

Systematics of the Chytridiomyceta, Blastocladiomycota, and other zoosporic eufungal groups are heavily reliant upon cultured organisms, and the difficulty of their isolation has led only a handful of dedicated, patient researchers to study these fungi. Most of the systematic work on these taxa in the last 40 years was conducted by Joyce E. Longcore at the University of Maine, Martha J. Powell at the University of Alabama, their students, and collaborators. These research groups excelled in culturing these fungi and in training a new generation of zoosporic eufungal researchers, but the maintenance of the cultures has always been a concern, often reliant on soft money provided by outside parties interested in cultures, such as the amphibian pathogen Batrachochytrium dendrobatidis, for which the amphibian disease community is reliant upon for experiments. Additionally, neither the University of Maine nor the University of Alabama currently employs staff that is capable of maintaining the high standard of effort and attention provided by Longcore or Powell.

In 2018, we secured NSF funding for the transfer and upkeep of cryopreserved cultures of Chytridiomycota, Monoblepharidomycota, and Blastocladiomycota generated by Longcore and Powell to the University of Michigan’s Fungarium. We established the Collection of Zoosporic Eufungi at the University of Michigan (CZEUM) to safeguard this valuable resource, which includes 52 type strains and over 1000 cultures. D. Rabern Simmons, Ph.D. student of Longcore and current post-doctoral researcher with James, helped facilitate the transfer of cultures from Maine and Alabama, and Simmons has worked on the day-to-day operation and maintenance of the collection and database. The CZEUM continues to accession zoosporic eufungal cultures from Longcore, additional culture collections (i.e., Ralph Emerson’s Allomyces cultures from the Fungal Genetic Stock Center in Manhattan, Kansas), and other researchers interested in preserving their isolates. We hope that this resource will be useful to the mycological community and will continue to support amphibian disease researchers.

D. Rabern Simmons and Joyce E. Longcore with 1887 Improved Griffith Club Microscope once belonging to University of Michigan professor Frederick K. Sparrow.

The CZEUM website ( is now online with a searchable database and background information on the collection. Cultures can be purchased from the collection, starting at $100 each plus shipping, and orders will be completed within 4 to 6 weeks. The website (under construction) additionally provides resources for those interested in isolation, culture maintenance, and cryopreservation. We are actively growing the website to include a bibliography of zoosporic eufungal systematics occurring since Sparrow’s monographic work (1), micrographs of taxa/cultures, more background information on zoosporic eufungal researchers, and additionally molecular data as it is made available.

Martha J. Powell and William J. Davis collecting aquatic samples at Lake Nicols, Tuscaloosa, Alabama.

In a recent publication (2), we used the Oxford Nanopore Technologies (ONT) MinION device and software to sequence rDNA operon sequences, averaging 4739 bp in length, from 431 CZEUM cultures. The full sequence from each isolate was amplified from a single PCR reaction (3), and multiplexed pools of barcoded amplicons were processed to reduce the price of sequencing. Comparisons of 195 previously published 18S and 28S sequences from CZEUM cultures proved that ONT MinION sequencing generates 18S and 28S sequences 99.8% similar to Sanger sequencing, indicative of, on average, a single nucleotide error in each published sequence. This manuscript is the first step in fully molecularly characterizing the holdings of the CZEUM and includes the largest phylogeny of Chytridiomyceta and Blastocladiomycota compiled to date.


  1. Sparrow FK. 1960. Aquatic Phycomycetes. 2nd ed. Ann Arbor, Michigan: University of Michigan Press. 1187 p.
  2. Simmons DR, Bonds AE, Castillo BT, Clemons RA, Glasco AD, Myers JM, Thapa NA, Letcher PM, Longcore JE, Powell MJ, James TY. 2020. The Collection of Zoosporic Eufungi at the University of Michigan (CZEUM): Introducing a new repository of barcoded Chytridiomyceta and Blastocladiomycota cultures. IMA Fungus 11:20. doi:10.1186/s43008-020-00041-z
  3. Wurzbacher C, Larsson E, Bengtsson-Palme J, Wyngaert S Van den, Svantesson S, Kristiansson E, Kagami M, Nilsson RH. 2018. Introducing ribosomal tandem repeat barcoding for fungi. BioRxiv. doi:10.1101/310540
Peter M. Letcher preparing cryopreserved cultures at the University of Alabama for transport to the CZEUM.
CZEUM researchers Alex D. Glasco and Rebecca A. Clemons sorting cryopreserved culture shipments from the University of Maine.