Volatile Organic Compounds (VOCs) Produced By The Rhizosphere Actinobacteria Streptomyces Sp. and Amycolatopsis Sp. Strains and Their Antifungal Activity Against Colletotrichum Musae

Abstract Herein is reported the study on the antifungal potential of VOCs produced by actinobacterial strains from the rhizosphere of Caatinga plants. Twenty strains were screened for their ability to produce VOCs with growth inhibition (GI) potential against the phytopathogen fungus Colletotrichum musae . The most active VOCs were produced by Streptomyces sp. (ACTB-77) and Amycolatopsis sp. (ACTB-290). The effect of VOCs from ACTB-77 and ACTB-290 on the morphological structure of the fungus hyphae was investigated by SEM and revealed significant deformation of the fungal cell filaments, especially in the case of ACTB-290. VOCs produced by these two actinobacteria strains and the fungus under axenic and co-culture conditions were investigated using HS-SPME-GCMS combined approaches, and all data were analyzed by statistical methods. Most of the mVOCs were identified, representing 92-100% of total peaks areas. Linalool (38.53±5.19%) and geosmin (17.25±2.55%) were the major VOCs constituents from ACTB-77, while dimethyl disulfide (48.49±3.48%) and dimethyl trisulfide (21.14±3.50%) were the major VOCs compounds produced by ACTB-290. Statistical analyses of data from co-cultures showed that the VOCs profile of the experiment involving ACTB-77 was more influenced by the fungal VOCs while the experiment with ACTB-290 was more influence by compounds from the actinobacteria.