Isolation and molecular characterization of Bacillus megaterium ATCC 14581 and its effect on nitrogen fertilizer use reduction, growth and yield of baby corn

Despite the known benefits of biofertilizers, there remains a limited understanding of effective indigenous strains specifically adapted to baby corn cultivation. This study isolated, characterized and evaluated an indigenous strain, Bacillus megaterium ATCC 14581, from the baby corn rhizosphere to assess its potential as a plant growth-promoting rhizobacterium biofertilizer. Morphological, biochemical and molecular analyses confirmed the identity and nitrogen-fixing capacity of this strain. Laboratory assays demonstrated significant nitrogenase activity alongside effective phosphate solubilization and indole-3-acetic acid (IAA) production, indicating multifunctional plant growth-promoting traits. Field experiments conducted with varying chemical nitrogen fertilizer (CNF) reduction levels (0, 25, 50 and 75 %) and bacterial inoculation revealed that inoculation with strain ATCC 14581 significantly improved baby corn growth parameters, including biomass, cob length and yield components compared to non-inoculated controls. Importantly, the strain enabled up to a 50 % reduction in CNF use without compromising yield, thereby contributing to nutrient efficiency. Inoculated plants showed increased protein and phosphorus levels in edible corn cobs. The strain showed good adaptability to environmental stresses, including temperature, pH and salinity, supporting its practical application. These results underscore the potential of strain ATCC 14581 as a sustainable biofertilizer that can help reduce CNF input, improve soil fertility and promote climate-smart agriculture in baby corn production systems. Further research on large-scale application and long term soil health impact is recommended to optimize field implementation.