Screening and identification of novel halotolerant bacterial strains and assessment for insoluble phosphate solubilization and IAA production

Abstract

Abstract Background Salinity is typical in seashore soils due to the interruption of seawater in the groundwater. Soil microbes of coastal regions play a vital role in increasing plant yields. Microbe-plant associated growth and its wide spectrum with soil environment remain one of the prime factors in agriculture for field application. Making such, in this study, very precise research work is outlined to serve microbial-based solution for solubilizing the insoluble phosphate under various harsh environmental conditions and IAA production. Salt-affected soils along the coast of Bay of Bengal, Sundarbans, India, have been collected. Results A total of five isolates effectively solubilize the considerable amount of Tri-calcium phosphate {TCP, (Ca3PO4)2} ranging from 50.67 to 116.66 P2O5 parts per million (ppm) under optimized conditions, i.e., pH 8.0, 5 to 10% saline and 30 °C temperature. Out of five, three produced Indole Acetic Acid (IAA) ranging from 0.054 to 0.183 (g l−1). Identification of isolates has been carried out by morphology, biochemical characterization and 16S rDNA sequencing. Among the sequenced isolates, 1 belonged to Firmicutes, 3 were Proteobacteria and 1 was Actinobacteria. Conclusion This is the first report which shows the presence of phosphate solubilizing activity by the member of the genus Halomonas and Halobacillus from the study site. These stress-tolerant bacteria will deliver reliable and cost-effective methods to overcome the existing scenario of saline-affected agriculture.

Keywords

• Saline soil
• Stress-tolerant bacteria
• Phosphate solubilizing bacteria
• IAA producing bacteria
• 16S rDNA