Welcome back to March Microbe Madness and the SEMI-FINALS!!! We have two excellent (and CLOSE!) match-ups for this penultimate round, so buckle up and get your popcorn ready. First up, it’s a showdown between the Bacterial division champ, Pseudomonas, and the Archaeal division champ, Nitrosarchaeum koreense. These two stalwart microbes will be battling it out in the HUMAN GUT.

Welcome back to the QUARTER FINALS of March Microbe Madness! First up, the final two Bacterial Division competitors: Escherichia coli K12 and Pseudomonas face off at the OCEAN SURFACE. E. coli has been floating around aimlessly since vanquishing Lactobacillus in the Round of 16. This remains an inhospitable environment for E. coli, who relies on being transmitted back to a host’s warm, nutrient-filled, anaerobic intestine relatively quickly.

Last up, we have the WILD CARD DIVISION. Our first match up is between the current class favorite, the Tardigrade, and the lesser-known and less charismatic Paceibacteria. These two will be facing off in a FRESHWATER LAKE. It seems like the random number generator likes Tardigrades too - its first battle was in a freshwater lake, which is a preferred habitat for the water bears. Our tardigrade is walking along, searching for some moss to munch on.

Now on to the EUKARYOTE DIVISION! Our first battle is between the parasitic Trypanosoma and the photosynthetic alga Lotharella oceanica. These two will be battling in the HUMAN GUT. This is good news for Trypanosoma, which can be spread via infected foods. From within the gut, it moves through the gastric epithelium and into the blood system where it multiplies.
pubmed.ncbi.nlm.nih.gov/18234547/

Next up, we have the ARCHAEAL DIVISION! Facing off first, we have Methanosarcina versus ANME archaea in SOIL. Methanosarcina just came from a grueling contest with Methanoregula, and is a bit battered by its time in the open ocean. Soil isn't much better, as methanogens rely on anoxic (no oxygen) conditions for methanogenesis, and soil is generally aerated.

Welcome back to March Microbe Madness! It's the round of 16, with eight fierce battles coming up. We will kick it off with the BACTERIAL DIVISION. First up, we have two microbes living in, on, and around us: E. coli stomped Dehalococcoides in soil, while Lactobacillus is fresh off a victory over Geobacter in the human gut. We're teleporting both competitors to the OCEAN SURFACE (via sewage pipe).

Final division, and anything can happen - it's the WILD CARDS! First up, we have Fuligo septica, the "dog vomit" slime mold versus last year's runner up, the Tardigrade, or water bear. These two multicellular microbes will be battling in a FRESHWATER LAKE. There's a disconnect in charisma here - Fuligo is an oozing heap of (well organized and optimized for survival and nutrient exploitation) vomit-like goo, while the Tardigrade is simply adorable. If you don't look too closely at its nightmare face.

It's time for the EUKARYOTE DIVISION, filled with a delicious diversity of single celled protists. Did you know the vast majority of eukaryotic diversity is found within the protists? Multicellular life is a small slice of a modest branch on the tree of life. Our first battle is between two gnarly parasites - Giardia and Trypanosoma. These two will be battling it out in one very unfortunate HUMAN GUT.

Next up, and new thread - we have the ARCHAEAL DIVISION! First from this Domain are Methanoregula and Methanosarcina, two methanogenic compatriots who will be battling in the SURFACE OCEAN. The ocean surface is covered in a thin biofilm dominated by photosynthetic algae and cyanobacteria. This oxic, high-light environment is responsible for more than half of the oxygen production on the planet.
Too bad both of our methanogens are strict anaerobes!

LET'S GET READY TO RUMBLE!
It's Round One of March Microbe Madness, and our 32 fantastic yet tiny competitors are ready to fight it out for microbial glory. But first, a quick recap of the rules. Each pair of mighty microbes will face off in one of four randomly selected environments: soil, ocean surface, freshwater lake, and the human gut.