The present invention relates to a process for the production of prodigiosin using Serratia marcescens by solid state fermentation. The present process provides a high productivity and concentrated prodigiosin production cost effectively under solid state fermentation conditions using agro-industrial residues. It involves cultivating the selected strain of Serratia marcescens aerobically under media conditions which are not strictly acidic or alkaline and are close to neutral, with a predetermined moisture content of 55-80% v/w and uses agro-industrial residues as a support, growth & metabolism. The process also uses addition of amino acid initially in fermentation medium and in 4-18 h old fermented medium for high productivity along with small amount of mineral salt supplementation. The process is carried out at a temperature range of 20-35°C for a period extending up to 54 h. The present process is simple to operate and offers a major advantage in the fact that it requires relatively cheaper substrates for producing prodigiosin.
