Novel Pseudomonas Strain for the Treatment of Iron-Deficient Soil

Background

The correct nutrition in crops is one of the most important challenges in agriculture. A poor nutrition management can lead to different diseases in crops, such as iron chlorosis, one of the most common diseases, that affects 30% of the crops in the world.

The current strategies to increase bioavailable iron content go in 3 ways: the addition of iron as a nutrient, acidification of the soil or the application of chelating agents. This strategy is efficient for the control of chlorosis; however, it has two characteristics that prevent its wide use; high cost and low degradability of chelators, restricting its use to extreme chlorosis events. For its part, the recalcitrance of these chelators allows them to reach underground water bodies, compromising their quality, since, during the infiltration process, they carry heavy metals. Studies have shown the benefits of using biological chelators or siderophore-producing microorganisms for plant growth since they can increase the concentration of iron in the plant.

Siderophores are iron transporters that can be secreted by bacteria, fungi, and plants to meet the cellular demand for iron. To obtain pyoverdine, production strategies use high-cost equipment, generating an expensive final product.

The genome of a recently isolated strain of Pseudomona chilensis, ABC1, encodes certain molecules that confer the ability to secrete siderophores. The objective is to produce strain ABC1 as an organic amendment for plant nutrition with emphasis on improving iron bioavailability in agricultural crops by developing a Pseudomonas formulation that can be effectively stored, distributed, and applied to different agricultural crops.

Technology Overview

The technology corresponds to a novel strain of Pseudomonas, Pseudomonas sp., that produces pyoverdine-type siderophores and is potentially at an industrial level that can be used in the agricultural industry as an input. Initial proof of concept has shown the effect on blueberry and tomato seedlings, where there was an increase of almost 3 times the wet weight for the tomatoes (Figure 2), while in the blueberry seedlings, the increase was twice its weight compared to the untreated ones (Figure 3).

The bioreactor for the production of this bacteria does not require sterile conditions, iron contamination control, or pH-based growth control method. In fact, it has been demonstrated that this strain can be grown in tap water. This strain can be produced in a reactor with aeration (Figure 4), or in a reactor without aeration (Figure 5).

The strain Pseudomonas chilensis ABC1 is deposited in the Chilean collection of Microbial Genetic Resources with accession number RGM2961.

Benefits

• Its application as biofertilizer has initially demonstrated an increase in plant growth due to higher iron bioavailability.
• High production efficiency of pyoverdine-type siderophore, even in the presence of iron.
• Siderophores can act as efficient activators of induced systemic resistance systems in plants, as well as protect the plant from different pathogens.
• In order to obtain biomass from the bacteria in question, the technical (operational) and nutritional (culture medium) requirements are reduced, providing a low production cost.

Applications

It can be used for any crop where iron supply is required to stimulate plant growth and prevent iron chlorosis. Alternatively, it can be used as a bioremediation agent, since it can precipitate Fe, Co, Cu and Mn. It has been tested on tomatoes and blue berries plants.

So far production assays have yield in aerated cultures a pyoverdine concentration of 35 mg/L and in the non-aerated culture 80 mg/L, 300 hours after the inoculation. The cultures were inoculated at 1% with a previous culture with concentration of 10 raised to power 8 UFC/mL.

Opportunity

We are looking for the opportunity to transfer our technology, begin commercial relationships with partners and achieve licensing.

Patents

• PCT WO2021258227A1, European patent application pending.

IP Status

• Patented

Seeking

• Development partner
• Commercial partner
• Licensing