OICC Press Journal of Nanostructure in Chemistry 2193-8865 11 4 (December 2021) 2021 01 20 Isolation of antimicrobial Tridecanoic acid from Bacillus sp. LBF-01 and its potentialization through silver nanoparticles synthesis: a combined experimental and theoretical studies 10.1007/s40097-020-00385-3 EN Swapan Kumar Chowdhury Department of Botany, Plant and Microbial Physiology and Biochemistry Laboratory, University of Gour Banga, Malda, West Bengal, 732 103, IN Department of Botany, Balurghat College, Balurghat, West Bengal, 733101, IN Department of Botany, Balurghat College, Balurghat, West Bengal, 733101, IN Tanmoy Dutta Department of Chemistry, JIS College of Engineering, Kalyani, West Bengal, 741235, IN Asoke P. Chattopadhyay Department of Chemistry, University of Kalyani, Kalyani, 741235, IN Narendra Nath Ghosh Department of Chemistry, University of Gour Banga, Malda, West Bengal, 732 103, IN Subhamoy Chowdhury Department of Chemistry, University of Gour Banga, Malda, West Bengal, 732 103, IN Vivekananda Mandal Department of Botany, Plant and Microbial Physiology and Biochemistry Laboratory, University of Gour Banga, Malda, West Bengal, 732 103, IN Journal Article 2021 01 20 Abstract Tridecanoic acid (TDA), an antimicrobial compound, was isolated from Bacillus sp. LBF-01 and purified with the help of column and multidimensional liquid chromatography (MDLC), and characterized by Thin-layer chromatography (TLC), Electrospray Ionisation Mass Spectrometry (ESI–MS), Ultraviolet–Visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) spectroscopic studies. Isolated TDA was potentialized through the synthesis of silver nanoparticles (AgNPs). UV–Vis, FTIR, and TEM analysis showed that synthesized AgNPs were stable, monodispersed, and spherical shape of average 19 nm diameter. Theoretical simulation using Density Functional Theory revealed that AgNPs were stabilized by the tridecanoate form of TDA with a binding energy of 59.9 kJ/mol. Both TDA and AgNPs showed strong antifungal and antibacterial activities against the plant and human pathogenic organisms, however, AgNPs showed higher antimicrobial efficacy than TDA. Synergistic activity of TDA and AgNPs with a fungicide (Bavistin) and antibiotics (Streptomycin and Ciprofloxacin) showed enhanced antimicrobial potency in the range of 20–32%. TDA and AgNPs cause severe morphological abnormalities in Fusarium oxysporum as observed under the light microscope. Hence, the study reveals that the antimicrobial TDA produced by Bacillus sp. LBF-01 have disease control potentiality, and also the TDA stabilized AgNPs have much higher antimicrobial efficacy against the target pathogens that could be utilized in plant and human diseases control. Graphic abstract