Microbiologically produced surfactin as a factor limiting the use of pesticide against cereal pests

Abstract

The use of pesticides in plant protection is vital in order to acquire food, however, it involves contamination of the environment. The purpose of this paper was to verify the use of the surfactant – surfactin, synthesised by the Bacillus subtilis natto BS19 strain as a measure in the biocontrol of cereal pests. The possibility of using trub as a substrate in the biosynthesis of this compound was investigated. The ability of pest feeding, survival outcomes and the number of laid eggs in response to lambda-cyhalothrin and surfactin in different concentrations were assessed. The most promising results were received after applying a solution containing 46 mg/L of surfactin and 75% of the maximum pesticide dose. After applying the product, a reduction of leaf damage was found to be around 59% and 67% regardless of, while after applying only the pesticide solution: 45% and 57% in Oulema melanopus and Oulema gallaeciana respectively. Applying the same variant of product containing surfactin limited the survival outcomes of insects by around 80%, and after applying the pesticide by 60%. Thus, it can be inferred that an addition of a trub-based lipopeptide in an optimal concentration may minimise the used pesticide dose and therefore limit feeding and survival outcomes of Oulema spp., which is lucrative in terms of ecology and economy. Trub may constitute a substrate for the biosynthesis of surfactin of stable surface-active properties over a wide temperature and pH range of the environment