Isolation and Characterization of Prospective Salt Tolerant Bacteria With Plant Growth Promoting Properties From Mangroves of Sundarban, West Bengal, India

Increasing soil salinity acts as a major abiotic stress for crop plants. Increasing global temperatures are leading to greater evaporation from soil, along with change in rainfall patterns, which is resulting in reduced soil water availability for crop plants and increased soil salinity. Consequently, crop plants face water and nutrient shortage leading to yield losses. In fact, crop plants cannot be grown easily on such saline soil without some form of remediation. Plant Growth Promoting Rhizobacteria (PGPR) have shown prospective results in this regard. Halotolerant PGPRs have the ability to grow in such saline soils, while providing plant roots in the vicinity with growth nutrients and hormones. In the present study, we obtained six bacterial isolates from mangrove pneumatophores of Aegialitis rotundifoliaRoxb. and Ceriops tagal C. B. Rob. with associated rhizobial soil from Kshetra Mohanpur site in the Sundarbans of West Bengal. They were screened for salt tolerance, nitrogen fixation, phosphate solubilizing, potassium solubilizing and auxin synthesizing ability. Two of the six isolates showed all these properties. Hence, we propose their use as halotolerant PGPR biofertilizers for soil bioremediation.