Stress induced phosphate solubilization in bacteria isolated from alkaline soils

Area of Science:

• Microbiology
• Soil Science
• Biotechnology

Background:

• Phosphate solubilizing bacteria (PSB) are crucial for improving phosphorus availability in soils.
• Chickpea rhizospheric and alkaline soil environments harbor diverse microbial communities with potential agricultural applications.

Purpose of the Study:

• To isolate and characterize phosphate solubilizing bacteria from chickpea rhizosphere and alkaline soils.
• To evaluate the in vitro phosphate solubilization efficiency of selected bacterial strains under various conditions.
• To identify the most effective PSB strain for potential use in agriculture.

Main Methods:

• Isolation of bacterial strains from chickpea rhizosphere and alkaline soils.
• In vitro screening of phosphate solubilization activity using various carbon and nitrogen sources.
• Assessment of PSB efficiency under extreme conditions (high salt, high pH, high temperature).
• Analysis of factors influencing phosphate solubilization, including acid production, Ca(2+), and EDTA.

Main Results:

• Four phosphate solubilizing bacteria (NBRI0603, NBRI2601, NBRI3246, NBRI4003) were successfully isolated.
• All strains exhibited varying degrees of phosphate solubilization, influenced by carbon and nitrogen sources.
• Strain NBRI2601 demonstrated superior phosphate solubilization under 10% salt, pH 12, and 45°C.
• Acid production contributed to, but was not the sole mechanism of, phosphate solubilization.
• Low concentrations of Ca(2+) and EDTA enhanced phosphate solubilization by the tested strains.

Conclusions:

• The isolated bacterial strains possess significant potential for enhancing phosphorus availability in soils.
• Strain NBRI2601 is a promising candidate for agricultural applications due to its robust phosphate solubilization capabilities.
• Understanding the mechanisms and optimal conditions for PSB activity can aid in developing sustainable agricultural practices.