The underpinning research "Monitoring the spatial-temporal distribution of secondary metabolites produced by the entomogenous fungus Beauveria brongniartii with particular reference to oosporein" was undertaken by Butt in 1999. It was clear, following publication of the paper in 2000, that although guidelines existed for risk assessment of conventional chemical pesticides, no such guidelines existed for fungal BCAs or their metabolites. This was problematic for the registration and commercial development of fungal BCAs. Regulators and industry needed reassurance that the metabolites did not enter the food chain posing a risk to humans and the environment.
The EU-funded projects BIPESCO (1999-2001) and RAFBCA (2001-2004), within which Butt played a pivotal role, created the framework and understanding of the health and environmental risks associated with EPF being developed as BCAs. Within BIPESCO, Butt identified key EPF metabolites, demonstrating inter- and intra-specific variation in metabolite production. The BIPESCO-RAFBCA teams showed that EPF produce many metabolites, often in extremely small quantities, making risk assessment extremely expensive and deterring industry from developing these products. This was compounded by the very few commercially available standards.
Butt co-ordinated development of methods and tools to isolate, characterise and quantify metabolites from disparate substrates (fungal culture media, crops and insect hosts). Different toxicity testing systems were evaluated as an alternative to the murine model. The Ames and new Vitotox assay systems were compared and confirmed that EPF did not secrete genotoxic compounds. Destruxins, major metabolites of Metarhizium, and the cuticle degrading protease Pr1 were shown to be useful quality control markers with attenuated/degenerate cultures producing little or no destruxin/Pr1.