Spirulina

Spirulina (Arthrospira) transforms the cyanobacterial photosynthesis engine into human food. This filamentous cyanobacterium has been harvested as food for centuries—Aztecs collected it from Lake Texcoco, and Kanembu people still harvest it from Lake Chad. Modern cultivation produces thousands of tons annually for health food markets, animal feed, and aquaculture. Spirulina represents cyanobacteria domesticated for human purposes.

The organism offers remarkable nutritional density: 60-70% protein by dry weight (higher than any conventional food), complete amino acid profile, vitamins, minerals, and antioxidants. Spirulina converts sunlight to protein more efficiently than any agricultural crop—it produces 20 times more protein per hectare than soybeans. This productivity, combined with ability to grow in alkaline water unsuitable for agriculture, positions Spirulina as a potential solution for food security challenges.

Spirulina cultivation exemplifies biological manufacturing. The organism grows in simple mineral solution plus sunlight and CO2, doubling biomass in 2-5 days. No arable land required; wastewater and industrial CO2 can serve as inputs. The alkaline conditions Spirulina prefers discourage contaminants, simplifying cultivation. NASA has studied Spirulina for space life support systems—its efficiency in closed-loop recycling approaches theoretical limits. Understanding Spirulina's success informs broader efforts to harness biological productivity for human needs.