Internet of Things (IoT)-Driven Fermentation System for Enhanced Cordycepin Production in Cordyceps militaris (Ascomycetes) under Hypoxic Conditions

Cordycepin, known for its tumor-suppressive and antiviral properties, has garnered attention due to its therapeutic and biological potential. Current Cordyceps militaris - based cordycepin production methods involve time-consuming and cost-intensive solid-state fermentation. Using an internet of things (IoT) architecture, we developed an active air-feed regulation fermentation system (AAFRFS) to detect CO2 emitted during C. militaris submerged fermentation. Equipped with a microcontroller unit and proportional-integral-derivative plus pulse-width modulation technology, the AAFRFS also regulates the air supply, inducing hypoxic stress to enhance cordycepin production. Our system uploads all fermentation data to a cloud database. After 14 d of fermentation (volume 5 L) at 3000 ppm metabolic CO2, cordycepin levels exceeded 1.44 g/L (yield: 103.2 mg/L/d). Hypoxic stress promoted earlier cordycepin production. Utilizing big data with an alert mechanism enabled the early detection of microbial contamination within a 12- to 24-h period. Principal component analysis revealed a positive correlation between temperature and CO2 concentration, suggesting that temperature fluctuations likely affect the respiration rate of C. militaris, thereby altering CO2 levels. Our findings may help optimize fermentation strategies not only for C. militaris but also for other fungal strains.