Though I generally find the establishment of state birds and trees and whatnot to be a rather pointless exercise, as an aspiring microbiologist, I cannot help but be charmed by the concept of a "state microbe". As Moselio Schaechter wrote on the Small Things Considered blog (back in 2010, when Wisconsin was deliberating over whether or not it should lay claim to Lactococcus lactis), recognizing these organisms does at least have the potential to promote greater awareness of the microbial world, particularly among young people, and perhaps on some small level, it generates additional general interest in funding research on their vital importance to both nature and human society.
In 2013, Oregon became the first state to designate its microbial representative, choosing Saccharomyces cerevisiae due to (in the words of the official legislation) "its importance to the livelihood and well-being of the people of this state" and its vital role in beer-making (Oregon being, according to the resolution, "an internationally recognized hub of craft brewing.") I suppose that as far as microbes go, S. cerevisiae certainly plays a significant role in human culture. Beyond its pivotal role as a model organism in a variety of biological fields, it constitutes an essential player in the production of fermented products like leavened bread and virtually all alcoholic beverages (not just beer). Indeed, the yeast should be considered a fungus of great esteem that any state could take pride in associating with.
Therein lies the problem of making it Oregon's state microbe: virtually any state could claim a legitimate connection to this supremely versatile organism. True, one might make the argument that the widespread use of streptomycin to treat tuberculosis makes New Jersey's chosen bacterium, Streptomyces griseus, similarly low-hanging fruit for state microbe status; however, New Jersey can at least claim that streptomycin's utility as an antibiotic was uncovered at its state university, whereas credit for "discovering" Saccharomyces cerevisiae (after thousands of years of use) arguably goes to Frenchman Louis Pasteur, who was definitely not a native Oregonian.
"But Miranda," you might be thinking. "Maybe Oregon doesn't have a significant connection to any other distinctive microbe. Maybe Saccharomyces cerevisiae was the best they could manage, given the circumstances."
That, dear reader, is where you would be wrong. Enter Armillaria ostoyae and Oregon's lovingly nicknamed, "Humongous Fungus."
On the surface, A. ostoyae may seem like an odd choice for state microbe. Unlike the relatively benign S. cerevisiae, A. ostoyae is first and foremost a plant pathogen that causes serious and often fatal root diseases in conifers, particularly the grand fir (USDA). Furthermore, it is hardly endemic to the state, appearing elsewhere in the U.S. and several other countries in the Northern hemisphere (Cleary et al.).
However, Oregon does have the distinction of harboring the largest living A. ostoyae individual in the world: the "Humongous Fungus" of the Malheur National Forest (USDA). In fact, this 3.7 square mile, 1,900-8,650-year-old behemoth is considered by many researchers to be the most massive living organism in the world (BBC). The irony of choosing such an organism as a state "microbe" seems too sweet for the Oregon legislature to ignore, especially since highlighting this unique feature seems like the perfect way to bolster its tourism industry. After all, you can physically see the fungus in various places throughout Malheur National Forest: those with keen eyes can pick out its dark, threading rhizomorphs (a form of tissue that allows the fungus to spread through dirt to new hosts) on exposed roots of fallen trees or white, streaky mycelial felts beneath the bark of dead or dying host plants (USDA). For still those put off by the idea of advertising the state's ginormous plant pathogen, like Saccharomyces cerevisiae, Armillaria ostoyae even has culinary utility in the form of its honey mushrooms, which (though not as popular as those of other Armillaria) are edible and can be enjoyed cooked (BBC).
As Oregon seems unlikely to stake its claim on Armillaria ostoyae any time soon, Washington State (which has yet to select a microbe for itself) should take note, as it has some similarly massive individuals it could easily capitalize on (BBC). One way or another, this distinctive mycological treasure should get a little more love (even if it's tempered by its status as disease-causing, tree-killing pest) from the states it calls home.