Isolation and identification of an antifungal compound from endophytic Streptomyces sp. CEN26 active against Alternaria brassicicola

Abstract

2,5-Bis(hydroxymethyl)furan monoacetate (BHMF-OAc) compound was isolated from the culture filtrate secreted by Streptomyces sp. CEN26, an endophytic actinomycete found in the root nodes of Centella asiatica (L.) Urban. The compound was purified using various chromatographic techniques and bioassay-guided fractionation. The compound was then identified through a structural characterization using 1H, 13C-NMR and MS analysis. After the purification and identification process, a series of experiments were conducted in order to test whether the compound affected conidial germination of Alternaria brassicicola. Findings show that the compound inhibited and deformed the conidial germination of A. brassicicola. Its minimal inhibitory concentrations of MIC90 and MIC50 were found to be 100 and 25 ppm respectively. Further experimentation show that the aforementioned concentrations of MIC90 and MIC50 completely suppressed the appressorium formation of the fungal pathogen. Therefore, the BHMF-OAc compound does have antifungal properties that help protect plants from infection by A. brassicicola. Significance and Impact of the Study: Endophytic Streptomyces sp. CEN26 produces 2,5-bis(hydroxymethyl)furan monoacetate (BHMF-OAc), which is a compound that inhibits the infection process of Alternaria brassicicola in cabbage. Such an antifungal property would allow for the use of the BHMF-OAc as an alternative to chemical fungicides.