John Wertz

John Wertz


  • B.S. in Biology, Calvin College, 2001
  • Ph.D. in Microbiology, Michigan State University, 2006

Professional Experience

After graduating from Calvin College in 2001, John went to Michigan State University to complete a Ph.D. in Microbiology, there he focused on the sub-field of microbial ecology. After completion of his Ph.D., he went on to a postdoctoral position, also at Michigan State, doing research in a developing (as-yet-unnamed) field where microbial ecology meets medical microbiology. As part of his postdoctoral experience, he jumped at the opportunity to teach an introductory biology course for biology majors, which consisted of a class size of 250 students. Jumping away from such large class sizes (among other things), he sought refuge back at Calvin where he has been teaching since 2007.


At Calvin Professor Wertz teaches the Phage Research course, Microbiology, and Medical Microbiology. Others areas of scholarly interest include the history of science, and how disease epidemics have shaped world history.

While not at Calvin, he enjoys spending time outdoors with his family, boating, swimming, biking, and hiking. An avid music lover, he is often found at various concerts around Grand Rapids or dancing (badly) to music in his office.

Academic interests

Dr Wertz's research interests include investigating bacterial symbioses within complex ecosystems. He is particularly interested in the biochemical basis for microbe-microbe and host-microbe symbioses, which includes the detection and cultivation of novel bacteria and bacteriophage diversity. As a model, he uses the termite gut (Reticulitermes flavipes) which contains as many as 700 different species of bacteria that interact in a complex web with each other and with the insect host. He has been successful in isolating many novel bacteria from the termite, including members of the elusive bacterial division Verrucomicrobia. With collaborators Corrie Moreau (Field Museum), Jacob Russell (Drexel University) and Scott Powell (George Washington University) he is also taking his knowledge of the termite gut and applying it to the herbivorous turtle ant (Cephalotes) system. Given the relatively nutrient-poor diet of this group of ants, his research focuses on how symbiotic bacteria have impacted the impressive diversification and ecological success of these insects.


Research and scholarship


  • Genomic and physiological characterization of the Verrucomicrobia isolate Diplosphaera colitermitum gen. nov., sp. nov., reveals microaerophily and nitrogen fixation genes. Wertz JT, Kim E, Breznak JA, Schmidt TM, Rodrigues JL. Appl Environ Microbiol. 2012 Mar;78(5):1544-55.
  • Cluster K mycobacteriophages: insights into the evolutionary origins of mycobacteriophage TM4. Pope WH, Ferreira CM, Jacobs-Sera D, Benjamin RC, Davis AJ, DeJong RJ, Elgin SC, Guilfoile FR, Forsyth MH, Harris AD, Harvey SE, Hughes LE, Hynes PM, Jackson AS, Jalal MD, MacMurray EA, Manley CM, McDonough MJ, Mosier JL, Osterbann LJ, Rabinowitz HS, Rhyan CN, Russell DA, Saha MS, Shaffer CD, Simon SE, Sims EF, Tovar IG, Weisser EG, Wertz JT, Weston-Hafer KA, Williamson KE, Zhang B, Cresawn SG, Jain P, Piuri M, Jacobs WR Jr, Hendrix RW, Hatfull GF. PLoS One. 2011;6(10):e26750.
  • John T. Wertz, Natasha Isaacs-Cosgrove, Claudia Holzman, and Terence L. Marsh, “Temporal Shifts in Microbial Communities in Nonpregnant African-American Women with and without Bacterial Vaginosis” INTERDISCIPLINARY PERSPECTIVES ON INFECTIOUS DISEASES Volume October 2008, Article ID 181253
  • Lin, J.Y., Hobson, W.J., Wertz, J.T. Ventosimonas gracilis nov. sp. nov. a member of the Gammaproteobacteria isolated from Cephalotes varians ant guts representing a new family, Ventosimonadaceae fam. nov. within the order Pseudomonadales. International Journal of Systematic and Evolutionary Biology 2016;doi: 10.1099/ijsem.0.001068
  • Lin, J.Y., Russell, J.A., Sanders, J.G., Wertz, J.T. Cephaloticoccus, gen. nov., a new genus of Verrucomicrobia containing two novel species isolated from Cephalotes ant guts. International Journal of Systematic and Evolutionary Biology. 2016; doi: 10.1099/ijsem.0.001141.

In the news

Calvin biology professor receives grant to study ants’ guts

John Wertz has spent his career studying “good” bacteria and was recently awarded $479,000 from the National Science Foundation to continue his research.

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