In the quest for sustainable agriculture, scientists are turning to nature’s own toolkit to unlock vital nutrients for plants. A recent study published in the *International Journal of Agronomy* has shed light on the potential of certain bacteria to solubilize phosphate rock, offering a promising avenue for biofertilizer development. The research, led by José Abraham García-Berumen from the Department of Veterinary Medicine and Animal Science, could significantly impact the agriculture sector by providing an eco-friendly solution to phosphorus deficiency in soils.
Phosphorus is a critical nutrient for plant growth, but its availability is often limited due to its tendency to form insoluble compounds in the soil. Phosphate rock (PR), while abundant, has low solubility, which reduces its effectiveness as a fertilizer. This is where phosphate-solubilizing microorganisms come into play. These microbes can convert insoluble phosphorus into forms that plants can readily absorb, offering a sustainable alternative to chemical fertilizers.
The study evaluated six bacterial strains from the Burkholderia and Paraburkholderia genera for their ability to solubilize phosphorus from PR. Using two selective media—Pikovskaya (PVK) and National Botanical Research Institute’s Phosphate—the researchers assessed the bacteria’s effectiveness through halo formation on solid media and quantified soluble phosphorus in liquid cultures.
The results were striking. In liquid cultures, B. anthina (10 PEI) and B. gladioli (FB-1Ma3) showed the highest phosphorus solubilization, with values of 31.6±0.2 and 26.3±0.2 mg L−1, respectively. In contrast, B. contaminans (MSR2) exhibited the lowest solubilization at 6.44±0.7 mg L−1. Notably, B. gladioli did not form halos in solid media despite its strong performance in liquid culture, highlighting the limitations of halo-based screening methods.
“These findings underscore the importance of using multiple assessment methods to accurately evaluate the phosphate-solubilizing potential of bacterial strains,” García-Berumen explained. “Our results demonstrate that some strains may be overlooked if only solid media assays are used, which could lead to missed opportunities for biofertilizer development.”
The study also measured indole-3-acetic acid (IAA) production, a plant hormone that promotes growth. P. rhynchosiae (SCV21) and P. graminis (SCV16) yielded the highest IAA values, ranging from 4.1±0.9 to 10.6±1.4 μg mL−1. This dual capability—phosphorus solubilization and IAA production—makes these strains particularly promising for biofertilizer applications.
The commercial implications of this research are substantial. As the agriculture sector seeks to reduce its reliance on chemical fertilizers, biofertilizers offer a sustainable and environmentally friendly alternative. The selected Burkholderia sensu lato strains, with their proven ability to solubilize phosphorus and produce IAA, could play a pivotal role in enhancing crop yields in phosphorus-deficient systems.
However, the researchers caution that biosafety must be carefully assessed before these strains can be widely used. “While the potential is exciting, it’s crucial to ensure that these bacteria do not pose any risks to human health or the environment,” García-Berumen noted.
This study, published in the *International Journal of Agronomy* and led by José Abraham García-Berumen from the Department of Veterinary Medicine and Animal Science, opens new avenues for biofertilizer development and sustainable agriculture. As the agriculture sector continues to evolve, the integration of phosphate-solubilizing microorganisms could revolutionize how we nourish our crops, paving the way for a more sustainable and productive future.