Isolation and characterization of PGPRs from organic preparations

Abstract

Rhizobacteria have been described as plant growth promoting as they offer their plant hosts an addit ional fortification against pathogen by expression of multiple activities that directly and indirectly inhibit pathogens. Most microbial diversity of the soil ecosystem is confined to the rhizosphere. These rhizospheric microbes have the potential to stimulate plant growth and manage soil and plant health. Nowadays, management of the rhizosphere bacterial population has advanced toward the concept of plant growth promoting rhizobacteria (PGPR) owing to emergence of fungicide-resistant pathogens and health concerns for the producers and consumers. Using PGPR as bio-fertilizer is an efficient approach to replace chemical fertilizers and pesticides for sustainable cultivation. In the present study bacteria isolated from Amritpani and Panchagavya were analysed for their biochemical characters and molecular confirmation using molecular tool. The substrate utilization pattern showed that the characteristics of the majority of the tested strains share a similar pattern. However, few isolates displayed varied patterns. Identif ication of these isolates showed that most of them belong to genus Bacillus and Alcaligenes spp. This was further confirmed with sequencing of the 16s rDNA gene of the bacteria. The present study has resulted in the isolation of PGPRs Bacillus pumilus (CISH-PGPR96), Bacillus subtilis (CISH-PGPR102) and Alcaligenes faecalis (CISH-PGPR104) isolates that can be utilised for sustainable agriculture production.