Screening of several microalgae revealed biopesticide properties of Chlorella sorokiniana against the strawberry pathogen Phytophthora cactorum

Abstract

AbstractPresent agricultural production typically depends on the intensive use of synthetic pesticides with potentially harmful consequences for humans and the environment. To ensure food security for the rapidly rising global population it is necessary to develop more sustainable alternatives to synthetic pesticides. Microalgae possess a large diversity in antimicrobial compounds and are considered one of the most promising sustainable sources of novel biopesticides. Antimicrobial activities of 15 microalgae strains were investigated against a selection of seven common plant pathogens relevant to agricultural production. Several microalgae were identified to possess antimicrobial activity with an extract ofChlorella sorokinianashowing the strongest growth inhibition of the plant pathogenPhytophthora cactorum. Different pre-treatments like freeze-drying, solvents with different polarities, and extraction methods were analyzed in regards to the level of antimicrobial activity ofC. sorokiniana. The bestC. sorokinianaextract demonstrated potential for biopesticide application on strawberry leaves infected withP. cactorum. This study reveals the abundant potential of microalgae as natural biopesticide for organic or more sustainable regular agriculture.