What is Microdle?
Microdle is a word puzzle about food microbiology. You have eight guesses to identify a hidden microbe, and each guess shows which letters are in its name and which are in the right place.
When the game ends, a short card explains what the microbe is and why it matters in food.
Who is Microdle for?
Microdle is for food science students, microbiology learners, fermentation enthusiasts, and food safety professionals. You don't need to know the names already: after your second guess, Run Lab Assay unlocks hints one guess at a time, showing the microbe's class, where it's found, a clue, and finally its first letter.
What microbes are included?
Every game draws its hidden microbe from one shared list of organisms that matter in food, so the answer could be any of these:
- Foodborne pathogens: bacteria such as Salmonella, Listeria, and Escherichia, viruses such as norovirus, and parasites such as Toxoplasma.
- Spoilage organisms: microbes that break down fresh food, such as Pseudomonas in chilled meat and Botrytis on fruit.
- Fermentation microbes: the yeasts, molds, and bacteria behind bread, beer, yogurt, cheese, and vinegar, such as Saccharomyces, Lactobacillus, and Acetobacter.
Several genera fit more than one group. Penicillium spoils food but also ripens Brie and blue cheese, and Aspergillus includes both toxin producers and the koji mold used to make soy sauce.
Microbe field guide (spoilers: lists every possible answer)
- Acetobacter
- Gram-Negative Bacteria
- An aerobic bacterium that converts ethanol to acetic acid, which is how vinegar is made.
- Aeromonas
- Gram-Negative Bacteria
- A water-associated bacterium found in seafood, fresh produce, and other moist foods. Some species can cause gastroenteritis.
- Aspergillus
- Fungus
- Some species produce dangerous aflatoxins, but A. oryzae (koji) is safely used to ferment soy sauce, miso, and sake.
- Bacillus
- Gram-Positive Bacteria
- Spore-forming soil bacteria. B. cereus is best known for 'fried rice syndrome', caused by its heat-resistant toxins.
- Bifidobacterium
- Gram-Positive Bacteria
- An anaerobic gut bacterium often added to functional dairy foods as a probiotic.
- Botrytis
- Fungus
- A mold best known for gray mold spoilage of fruits and vegetables, and noble rot in certain dessert wine grapes.
- Brucella
- Gram-Negative Bacteria
- A zoonotic bacterium linked to unpasteurized milk, soft cheeses, and raw dairy products.
- Campylobacter
- Gram-Negative Bacteria
- Frequently associated with undercooked poultry. A spiral-shaped bacterium that is a major cause of gastroenteritis.
- Candida
- Fungus
- A yeast genus found in many environments. Some species occur in fermented foods, while others are opportunistic human pathogens.
- Clostridium
- Gram-Positive Bacteria
- Spore-forming, anaerobic bacteria. C. botulinum causes deadly botulism, while C. perfringens is a common cause of food poisoning.
- Cronobacter
- Gram-Negative Bacteria
- Survives in very dry environments and is a major concern in powdered infant formula.
- Cyclospora
- Parasite
- A protozoan parasite linked to contaminated fresh produce such as berries, herbs, and leafy greens.
- Enterococcus
- Gram-Positive Bacteria
- A hardy lactic acid bacterium found in fermented foods, the gut, and processing environments. Some species are opportunistic pathogens.
- Escherichia
- Gram-Negative Bacteria
- Its best-known species is E. coli. Most strains are harmless, but pathogenic strains such as O157:H7 produce dangerous Shiga toxins.
- Hepatitis
- Virus
- Stands for hepatitis A virus, which spreads through contaminated produce, shellfish, and infected food handlers.
- Klebsiella
- Gram-Negative Bacteria
- An opportunistic bacterium found in the environment, humans, and foods. Some strains are important antibiotic-resistant pathogens.
- Lactobacillus
- Gram-Positive Bacteria
- A genus of lactic acid bacteria used to make yogurt, sourdough, and pickles, and sold as probiotics.
- Lactococcus
- Gram-Positive Bacteria
- A lactic acid bacterium and one of the main starter cultures for cheeses around the world.
- Listeria
- Gram-Positive Bacteria
- A dangerous pathogen that continues to multiply at refrigerator temperatures. High risk for immunocompromised individuals.
- Mucor
- Fungus
- A mold found in soil and plants. Often causes food spoilage, but some strains are used in cheese ripening.
- Norovirus
- Virus
- The leading viral cause of foodborne illness worldwide. Highly contagious, often linked to infected food handlers.
- Penicillium
- Fungus
- Known for food spoilage and antibiotics. Specific strains are also used to ripen blue cheese, Camembert, and Brie.
- Pseudomonas
- Gram-Negative Bacteria
- A strict aerobe and a leading cause of rapid spoilage in refrigerated fresh meat and dairy.
- Rhizopus
- Fungus
- A common mold that quickly spoils bread and soft fruit. It is also used to ferment soybeans into tempeh.
- Rotavirus
- Virus
- A highly contagious gastrointestinal virus. Foodborne spread can occur through poor hygiene and contaminated ready-to-eat foods.
- Saccharomyces
- Fungus
- The main yeast used in baking, brewing, and winemaking. It converts sugars into ethanol and carbon dioxide.
- Salmonella
- Gram-Negative Bacteria
- A common bacterial cause of food poisoning, frequently linked to undercooked poultry and raw eggs.
- Shigella
- Gram-Negative Bacteria
- Highly contagious pathogen with a very low infectious dose. Often spreads through contaminated food, water, or poor hygiene.
- Staphylococcus
- Gram-Positive Bacteria
- Produces heat-stable enterotoxins in food. The toxin, not an infection, causes the illness, so severe symptoms start quickly.
- Streptococcus
- Gram-Positive Bacteria
- Some species cause illness, but S. thermophilus is a standard starter culture for yogurt and many cheeses.
- Toxoplasma
- Parasite
- A protozoan parasite associated with undercooked meat, especially pork, lamb, and venison, as well as contaminated produce.
- Trichinella
- Parasite
- A parasitic roundworm associated with undercooked pork, wild boar, bear, and other game meats.
- Vibrio
- Gram-Negative Bacteria
- A marine bacterium associated with eating raw or undercooked seafood, particularly oysters.
- Yersinia
- Gram-Negative Bacteria
- A psychrotrophic pathogen frequently associated with undercooked pork products.