Spirulina was a staple food and a source of protein in the Mexica diet, specifically Arthrospira maxima and Arthrospira platensis, a tiny aquatic plant considered the world’s healthiest superfood due to its exceptional nutritional value. This edible blue-green algae found in Lake Texcoco produces 15 times more protein per acre than soybeans, 35 times more than corn, and 70 times more than wheat. Because it grows in salty lakes, it doesn’t compete with other possible food sources. The Mexica collected the thick, blue-green algae from Lake Texcoco’s surface using poles, where the water’s salinity and alkalinity provided ideal conditions for its growth. The harvested algae was then dried into small, dense cakes, known as tecuitlatl, which were a valuable source of nutrients. Oral traditions suggest that these cakes were eaten with other staples like corn tortillas, beans, or mole to provide energy for long-distance travel. Source
Seems ideal for vat culture.