Development and formulation of azospirillum lipoferum and pseudomonas fluorescens as effective biological agents for enhanced agro-productivity

Abstract

Biofertilizer is a group of beneficial microorganisms used for improving the productivity of soil by fixing atmospheric nitrogen or by solubilizing soil phosphorus. They also stimulate plant growth through synthesis of growth promoting substances. In this present study, Azospirillum lipoferum is grown in Nitrogen free Bromothymol blue (Nfb) medium and Pseudomonas fluorescens in King's B medium. Bioprocess condition was optimized for both of the culture and found that Pseudomonas fluorescens has shown highest growth at 30⁰C in pH 8 after 72 hours of incubation where as Azospirillum lipoferum showed highest cell concentration at 31⁰C in pH 7, with incubation period of 72 hours. The optimized culture is mixed with different formulations of powder and liquid carrier such as Saw dust, Rice husk, Date seed powder, Matka khad, Jiwamrit and Beejamrit respectively. Shelf life study for 0, 30, 60, 90 and 120 days by cell counting and spread plate method showed that shelf life of the biofertilizer produced from Powder and liquid carriers had high amount of viable microbial population up to 120 days storage. Among biofertilizer based bio inoculants, Saw dust showed maximum population of 77x10⁹cfu/ml for Azospirillum lipoferum and 72 x 10⁹ CFU/ml for Pseudomonas strain on 120^th day and the liquid carrier Matka khad showed 85x10⁹ cfu/ml for Azospirillum lipoferum and 78 x 10⁹ CFU/ml for Pseudomonas fluorescens.