Biosolutions at OXITENO: Capabilities and Technologies for the Biopesticide Market

Biologicals are here to stay! Microbial formulations use in the field grow above any other segment in agriculture. Having an incredible growth rate by 13.68% and stands out in the main crops such as soybean, corn and sugarcane, expected to reach close to USD 20.59 billion by 2026 [1]. From 2010 on, biologicals entered as disease and insects crop management tools for row crops, which was an important milestone for this market consolidation. Biologicals are expected to be a common tool in the integrated management of farmers globally in the next decade.

Oxiteno has been positioned in the market with targeted biopesticides (living microbes and their metabolites, and other biostimulants). In Biosolutions Innovation Platform, Oxiteno works in the development of special components for bioprocesses, and formulations of microbes and metabolites as biopesticides, and dsRNA. In Biosolutions, and more specifically to biopesticide formulations, Oxiteno has worked on generating knowledge and internal capabilities to become a solution provider since 2017 and has now reached a state that enables product development, robust technical positioning and co-creation with our partners and customers. With a team of specialists and a complete structure of Research and Development, Oxiteno works alongside the industry to develop customized solutions according to these special active ingredients and application modals. In addition to a biological laboratory, the company's R&D Center in São Paulo/Brazil has capabilities to develop and test new technologies.

Oxiteno has consistently worked with microorganisms to understand which products can be applied safely and effectively, as well as how to formulate them to provide products and solutions for tank mix and in-can formulations. The use of microorganisms contributes immensely to the sustainability of agriculture, as biological products don’t leave pesticides residues in the crops. Indeed, biological residues are suitable for the soil microbiota, improving fertility.

The biocompatibility of the products is the first step to provide a toolbox of components for the formulator. Oxiteno published a review of the main methods to start a microbial formulation [2], also providing a new methodology for the fast and low-cost quantification of microbes on leaves, validated and published by ASTM. This study resulted from a robust study analyzing 50 different chemistries of our portfolio, aiming to understand how different molecules interact with different microbes and identify the limitations of the different chemistries to be applied on each microbe model. From this study, we identified molecules and their functionalization that are suitable for microbial formulations, and developed skills to design the preferential chemistries to be applied as dispersants, wetting agents, emulsifiers, or carriers to better address the challenges of formulators.

In general, the main causes of the loss of viability of microbes in a formulation are the air, water (humidity) and direct interaction with surfactants. Regardless of the best compatibility of some surfactant, a long time of direct exposure with microbes will lead to a harmful interaction with cells’ structures, thus decreasing shelf life. The formulation strategy here is how to delay these interactions by choosing the right molecules, including purification steps to avoid some by processes of its production whenever necessary. In this sense, the bioassay must be performed with components applied on the culture media with parameters evaluated during different stages of the microbial development, thus providing reliable results and information about how the products will interact with microbes. In summary, the answers from the study are split into:

(i) Incompatible – the molecule leads the microbes to viability loss, and the reasons underlying this behavior are identified (Could be the molecule itself, or byproducts of the molecule´s production?)

(ii) Biocompatible – and then separated as:

(ii.i) highly compatible – can be applied as a carrier or in encapsulation methods. However, the formulator must be careful as  these molecules (gums and some vegetable oils, for instance) can be consumed as carbon source by the microbes, which can lead to a microbial development within the package under certain conditions. Oxiteno has a unique line of green solvents based on raw materials of renewable and waste source of the agroindustry, specific for microbial formulations and background to indicate the better use of these products for a higher shelf life.

(ii.i) compatible at certain concentrations – here the challenge is to identify the minimum inhibitory concentration of the molecule and target it as the maximum to be applied in a formulation. They can be applied as emulsifiers, dispersants and co-dispersants based on raw material waste and renewable source. Besides these examples, Oxiteno has a broader portfolio for microbial formulations.

An example of how Oxiteno has worked with each component is given on Figure 1.

This study was performed with ATCC strains of the fungi species Beauveria bassiana, Trichoderma harzianium, and bacteria species B. subtilis, B. amyloliquefaciens, B. firmus, Pseudomonas chlororaphis, and compatibility assessed during their entire lifecycle.

These microbes were chosen based on relevance on the market and representing different metabolic/physiological, morphological and physicochemical models. This background allowed to propose the design of new chemistries and innovative strategies of formulation to work specifically with microbes and have been the basis of Oxiteno’s current innovation project pipeline. It allows not only the indication of the most suitable components for customer´s application, but the development of tailor-made solutions for the market.

Microbial formulations require additional cautious besides the usual physicochemical challenges, such as the integrity of extracellular matrix, electrolytes, final pH, inert filler, etc. All these components must be formulated to guarantee that the microbe will be kept in the dormant/inactive stage during storage and only start developing after application on the right target. It’s important to keep in mind that the performance of a formulation applied in a hydrophilic culture media is different from the substrate where the microbes will grow up in the field, which are mainly hydrophobic in nature (aerial part of the plant and root systems).

To achieve the better performance from the microbe strain, tank mix and in-can formulations cases were studied to identify the causes of viability loss and how to overcome them.

In-can formulations with a suitable shelf life can be achieved keeping the microbial cells apart from the fermentation debris and water. Package properties will decrease the interaction with air and a proper protection of the microbes by means of a suitable carrier or encapsulation is desirable to improve shelf life. Oxiteno has developed production processes [3] and products specifically for WDG formulations, and solutions for SC formulations of both bacteria and fungi species.

For tank mix, four main factors must be considered for a successful application of a bio-AI: (i) pH of the final solution, (ii) time in hours from the tank mix preparation until application, (iii) concentration of all the products in the tank, (iv) addition order of the components in the tank. After considering these factors, it’s possible to design the right compatibilization products with chemical AI, and other bio-based AI as well.

Oxiteno relies on its own capabilities for development, besides projects with partners for greenhouse and field trials for data generation and validation.

Oxiteno has structured capabilities to formulate microbes: a complete and dedicated laboratory of microbiology, library of microorganisms, microscopes, flow cytometer, besides laminar flow hoods and usual microbiology equipment. To better target microbial performance, it can be performed applications on leaves using the spray chamber to study the influence of different nozzles in the application of microbes, as well as to assess rainfastness resistance of the formulations. For better results, the applied plants are grown in a growth chamber where conditions such as temperature and humidity are controlled. To increase capacity, the construction of a greenhouse for the cultivation of plants used in tests is ongoing. Seed treatment coverages and germination trials are performed in Crop Solutions lab. Rhizotron root trials using target-plants are developed to assess the performance of the prototypes in seed treatment and in-furrow applications using different soil sources. Besides morphometry, plant physiological features are assessed with Oxiteno’s infrared gas analyzer combined with a fluorometer to assess the improvements in plant performance promoted by microbes.

Count on Oxiteno’s background, capabilities and people to the development of your microbial-containing formulations. For more information, please reach cropsolutions@oxiteno.com.

References

[1] Fortune Business InsightsTM 20. Agriculture Biologicals Market Size.

[2] Cardoso-Gustavson P et al. 2020. An introduction of techniques to aid in building microbial-containing formulations: from the selection of components to foliage application. Pesticide Formulation and Delivery Systems (ASTM International): 40: 104-127.

[3] Cardoso-Gustavson P et al. IP-pending. BR 10 2020 0246771. Formulation of water-dispersible granules containing microbiological actives and preparation method.

This article will be published in AgroPages '2021 Biologicals Special' magazine to be published this June.

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