Cobalt trace mineral nutrient

These effects are related to rapid metabolism of the sugar and can be prevented if the sugar is metabolized slowly. Trichoderma viride will produce as much cellulase on cellobiose as it does on cellulose if its metabolism is slowed by (1) suboptimum temperature and aeration, (2) deficiencies of mineral nutrients such as calcium, magnesium, or trace metals, or (3) excess of a mineral such as cobalt (23). 

At least thirteen mineral elements have been shown to be essential in human nutrition. These include calcium, magnesium, sodium, potassium, phosphorus, sulfur, and chlorine (principal mineral elements), and iron, copper, iodine, manganese, cobalt, and zinc (trace elements). It is uncertain as to whether fluorine, aluminum, and boron are essential nutrients. 

---