Azotobacter is a free-living nitrogen-fixing bacterium, which is used as a biofertilizer in the cultivation of most crops. A specific strain of Azotobacter chroococcum has been isolated from the rhizosphere of mulberry plant and tested by the CSR&TI, Mysore under in vivo and in vitro conditions and has found to be very effective. The laboratory has recommended application of the Azotobacter biofertilizer at the rate of 20 kg per hectare per year and this assures a substantial saving of nitrogen fertilizer (about 50 % reduction in N requirement). This indirectly reduces the costs involved in the silkworm rearing aspects as well as the soil health is improved by increased microbial activity.

The process of mass multiplication of the microbial culture and packing in polythene bags along with a carrier (preferably lignite or coal) has been standardized. The process ensures a minimum of 10⁸ viable cells of Azotobacter per gram of carrier on dry weight basis within 15 days of preparation and 10⁷ viable cells before the expiry date (As per the BIS norms). The shelf life of the biofertilizer is six months from date of manufacture. The Process requires locally available plant, machinery and raw materials for manufacture. The mass culture can be done by shake-flask or by using a fermentor depending on the investment capability. The culture is then mixed with the carrier material under hygienic conditions and packed immediately. The batch number and expiry date are immediately affixed on each bag. Normally, packets are available in 250 g, 500 g, 1.0 kg and 5.0 kg denominations.

The CSR&TI has conducted field trials of this biofertilizer in their Regional Stations as well as in the farmer's field. It has given good results and is widely accepted by the Sericulture Farmers of Karnataka, Tamil Nadu, Andhra Pradesh and Kerala under irrigated condition.

List of Machinery: Gyratory Shaker/Industrial Fermentor, S.S. Mixing Drum, Incubator Shaker, Autoclaves, Analytical Balances, Deep Freezer, Polythene Bag Sealing Machine, Research Microscope, Miscellaneous Laboratory Equipments, etc.