Spirulina is an edible micro-algae. It is toxic-free, rich in proteins and vitamins and has a high medicinal value. A simple and cheap technology has been developed for rural women to cultivate spirulina at home, requiring little space and investment. This can be a profitable industry as dried spirulina can be sold at about Rs. 300/- per kg.
Three mud pots of 35 to 40 litre capacity/25 sq.m. of exposed and protected space.
Bio-gas slurry and 2-3 grams of sea salt or chemical medium (Potassium dihydrogen Phosphate, Cooking Soda and Sodium Chloride); and Pure Spirulina Culture.
The three mud pots are buried upto their necks in the ground, filled with water mixed with the medium. Bio-gas slurry is the cheapest nutrient medium for spirulina culture. A small quantity of pure spirulina is put into the medium. (In the initial stage, the nutrient medium has to be supplied to the producer as stock-solution for ready mixing). The medium has to be stirred 3 to 4 times a day as the spirulina can not grow in a stagnant medium. The pots have to be exposed to sunlight as the spirulina takes 3 to 4 days to mature. The mature spirulina (When the pale medium turns into dark green) can be harvested by a simple cloth-filtration. After washing the spirulina in fresh water (to remove the adhering chemicals), it can be directly mixed with the chapatti / dough, chutnies, noodles, dais, vegetables etc. (about 2% by weight). Spirulina can be preserved by drying it in the shade. It must be dried immediately to preserve its quality and value.
Spirulina grown in 3 earthen pots of 35-40 litre capacity is sufficient to provide 2 grams per day (per person) high-quality spirulina powder to meet 100% vitamin A and 200% vitamin B-12 requirement, daily.
Dr. C.V. Sheshadri, Amm Marugappa Chmtiar Research Centre, Algal Division, Saverivyar Puram, Pudukkotai Dist., Tamilnadu