Isolation of efficient phosphate solubilizing bacteria capable of enhancing tomato plant growth

Authors: Sharon, Judee; Hathwaik, Leyla; Glenn, Gregory - Greg; IMAM, SYED - Flozyme Corporation, Inc; Lee, Charles

Submitted to: Journal of Soil Science and Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2016
Publication Date: 5/4/2016
Citation: Sharon, J.A., Hathwaik, L.T., Glenn, G.M., Imam, S.H., Lee, C.C. 2016. Isolation of efficient phosphate solubilizing bacteria capable of enhancing tomato plant growth. Journal of Soil Science and Plant Nutrition. 16(2):525-536.

Interpretive Summary: Phosphorus (P) is a macronutrient that is essential for plant growth and development. Since the concentration of available P in soil is lower than what is found in healthy plant tissues, the common agricultural practice is to apply P fertilizers. Consequently, P fertilizers have become the largest market for phosphorus worldwide. Due to the demand of agriculture on global stocks of P, it is estimated that the world will reach its maximum rate of quality mineral P production by 2040 at which point production will decline while agricultural demand will continue to rise. Since P supplies are not easily replenished, it is important to better utilize P reserves in the soil and reclaim insoluble, chemically-bound P. We have isolated microorganisms that are capable of releasing the insoluble P reserves in the soil and making this P available for plant growth. The implementation of this biofertilizer could dramatically decrease the use of P fertilizers.

Technical Abstract: Phosphorus is one of the three macronutrients that are essential for plant growth and development. Inorganic phosphorus (P), which can make up to 70% of the total P content in soils, can exist in calcium-, aluminum-, or iron-complexed forms that are unavailable for plant use. As a result, mineral phosphorus, P2O5, is often used as a fertilizer to supplement the nutrient for crop growth. To reduce the addition of mineral phosphorus to agricultural soils, research in naturally occurring phosphate-solubilizing microorganisms has been conducted for decades. This study found bacteria that solubilized phosphate at very high rates. The most efficient of the bacteria presented in this paper, Pantoea sp. Pot1, can solubilize tricalcium phosphate at a rate of 956 mg/L. Greenhouse experiments demonstrated that tomato plants with soil systems inoculated with Pantoea sp. Pot1 produced much higher biomass weights than those plants without any added bacteria.