Biologically Active Volatile Organic Compounds (VOCs) Produced by Rhizospheric Actinobacteria Strains Inhibit the Growth of the Phytopathogen Colletotrichum musae

Abstract

The antifungal potential of volatile organic compounds (VOCs) produced by actinobacterial strains Streptomyces sp. (ACTB-77) and Amycolatopsis sp. (ACTB-290) from the rhizosphere of Caatinga plants against Colletotrichum musae was investigated. VOCs produced by these microorganisms (axenic and co-culture) were investigated using headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Although no exclusive VOC peaks were observed in the co-culture with ACTB-77, the same experiment involving ACTB-290 yielded five new peaks, including two identified alcohols, suggested as bioreductive products of the corresponding ketones by the fungus. Statistical analysis revealed that co-culture ACTB-77/C. musae has a closer similarity to the fungus than to the actinobacteria, while the co‑culture ACTB-290/C. musae showed closer similarity to the actinobacteria. These confirmed the more pronounced antifungal activity of the ACTB-290 strain, as observed in the fungus growth inhibition experiments. The antifungal activity of ACTB-290 was associated to its sulfur-containing metabolites, while linalool was suggested as responsible for the ACTB-77 activity.

Strip intercropping with local crops increased Aconitum carmichaeli yield and soil quality

“…Both maize and rice intercropping could not substantially alter the soil microbial a diversity; however, it strongly influenced the microbial community structure. In the two intercropping systems, the potential functions of 28 potential beneficial genera included the following: the generation of IAA (Bal et al, 2013), nitrogen fixation (Hayat et al, 2010;Shahrajabian et al, 2021), soil mercury content reduction (Ustiatik et al, 2022), the degradation of polycyclic aromatic hydrocarbons (Zhao et al, 2021), antibacterial functions (Mosquera et al, 2020), antimycotic functions (De Brito et al, 2022), aluminum tolerance (Silambarasan et al, 2022), salt and alkali resistance , phosphate solubilization (Chhetri et al, 2021;Saadouli et al, 2021), siderophores (Jamalzadeh et al, 2021;Nie et al, 2022), nitrification (Peng et al, 2021), etc. In the control group, the potential functions of the 15 potentially beneficial genera were as follows: the nitrogen cycle (Zhang et al, 2022), antibiotic functions (Nakkeeran et al, 2021), heavy metal resistance (Zhai et al, 2020;Sharma et al, 2022), phosphate solubilization (Huang et al, 2021;Duan et al, 2022), improved photosynthesis (Katsenios et al, 2021), nitrification (Li et al, 2022), etc.…”

Characterization of Promising Antifungal Bioactive Compounds from Endophytic Actinobacterium, Streptomyces rochei OM182844

“…Streptomyces is an excellent reservoir for novel natural beneficial metabolites that can protect plant hosts from infection pathogens, including the VOCs, that protect plants directly or indirectly against phytopathogens through fumigation. These VOCs play a vital role in soil microbial relationships, especially antagonism and parasitism (de Brito et al, 2022).…”