Optimization and Standardization of Conditions for Production of Commercially Viable Formulation of Native Agrobacterium sp. UHFBA-218

Abstract

Studies were carried out for the mass multiplication of native Agrobacterium sp. UHFBA-218 (MCC 2101, NCBI: KC488176; deposited as UHFBA-218[Cherry 2E-2-2]) and Rhizobium rhizogenes strain K84 at different pH, temperature, incubation period, broth media and at different air supply. The most effective pH, temperature, incubation period, broth medium and air supply for both the isolates was 7.0, 25 °C, 4 days, yeast extract mannitol broth medium and 20 L/min, respectively. These parameters were further used for mass multiplication of these strains and mixing the multiplied bacterial inoculum for studying the viability of Agrobacterium sp. UHFBA-218 and R. rhizogenes strain K84 in different carrier media—white stone powder, carboxymethyl cellulose and activated charcoal during 6 months of storage at room temperature at three different locations, mixed in one part of broth culture in exponential phase having 270 ± 10 × 10¹² cfu/ml to two part of carrier and one part of broth culture mixed to five part of carrier and were compared for viable counts observed in different formulations kept at 4 °C for reference. White stone powder was superior to other carrier media tested under these studies. There were appreciable counts ranging from 34.67 to 103.3 × 10⁸ cfu/g after 6 months of room temperature storage at different locations. However, irrespective of strains, storage at 4 °C temperature provided maximum viability of 108.50 and 155.7 × 10⁸ cfu/g in white stone powder mixed in 1:5 and 1:2 ratios, respectively.