Calcite solubilizing, Multi-metal Tolerant Strain Isolated from Dolomite Affected Tea Garden Shows Plant Growth...

Area of Science:

• Agricultural Microbiology
• Soil Science
• Bioremediation

Background:

• Dolomite-affected soils pose challenges for agriculture due to their chemical properties.
• Sustainable soil reclamation requires effective microbial solutions.
• Plant growth-promoting bacteria offer a promising approach for soil amendment.

Purpose of the Study:

• To isolate and characterize soil bacteria with calcite solubilization and plant growth promotion traits.
• To identify microbes capable of tolerating multi-metal contamination and alkaline conditions.
• To evaluate the potential of isolated bacteria for reclaiming dolomite-affected tea plantation soils.

Main Methods:

• Isolation and screening of calcite solubilizing bacteria from soil.
• Molecular characterization of bacterial isolates (Lysinibacillus macroides NJCT2a).
• Assessment of metal tolerance, pH and calcium hydroxide stress endurance, and antibiotic resistance.
• In vitro evaluation of plant growth-promoting activities (ammonia, IAA, phosphate production).
• Seed germination and plant growth trials with Phaseolus vulgaris and Vigna radiata.

Main Results:

• Lysinibacillus macroides NJCT2a demonstrated significant calcite solubilization (4.78 index).
• The strain exhibited tolerance to copper, zinc, lead, iron, and aluminum, thriving under high pH and calcium hydroxide stress.
• NJCT2a showed plant growth-promoting activities including ammonia, indole acetic acid, and phosphate solubilization.
• The bacterium significantly enhanced seed germination (100%) and vigor index (850) for Vigna radiata.
• Soil application of NJCT2a led to increased plant height, root length, biomass, and chlorophyll content in Phaseolus vulgaris and Vigna radiata.

Conclusions:

• Lysinibacillus macroides NJCT2a is a robust bio-prospect with potential for dolomite-affected soil reclamation.
• The strain's multi-metal tolerance and plant growth-promoting abilities make it suitable for sustainable agriculture in challenging environments.
• NJCT2a can be utilized as a bioinoculant to improve soil health and crop productivity in tea gardens.