A major technical challenge facing the biopesticide industry is long-term room temperature storage stability of microbial active ingredients. Liquid formulations that are compatible with traditional agrochemical products are also highly desired. Developing room-temperature stable bioformulations has largely been trial and error by industry. Several different amendments (e.g., carriers, sugars, dispersants, surfactants, etc.) are used in practice, and each may individually or in combination have an impact on long-term stability of the microbial active ingredient. Here we present a rational approach for evaluating formulations of microbes using Pseudomonas fluorescens as an example. Our approach uses a partial factorial statistically structured screen that lends itself to mass screening of numerous amendments and combinations in parallel. The semi-high throughput screening platform can be adapted to evaluate different formulations for microbes or consortia of microbes of interest in order to determine suitable formulations that retain desirable active ingredient properties (e.g., viability). Here, the viability of P. fluorescens in various formulations was measured after storage at room temperature for two, four, and eight weeks using a 96-well assay that measures microbial growth via optical density. Viability results were then analyzed using a statistical approach that involved fitting models to the data and determining the amendments, combination of amendments, and interactions of amendments that showed the highest correlation with desired output (i.e., P. fluorescens stability). Such information can be used to remove non-useful amendments and “dial in” on a formulation that provides optimal stability. Using this structured approach, it was found that unique combinations containing ingredients such as trehalose, molasses, alginate, and arginine provided enhanced P. fluorescens stability compared to control formulations.

Fast, structured, adaptable approach to screen bioformulation amendments and stabilizers

250th National Meeting (2015)

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Fast, structured, adaptable approach to screen bioformulation amendments and stabilizers<br />