Isolation and Structural Determination of Bioactive Metabolites Produced by a Soil Bacterium, Arthrobacter sp. TAJX1902

As antimicrobial resistance persistently disrupts the treatment of microbial infection, identifying novel drugs with novel modes of action is critical to getting ahead of resistance. The primary goal of this project is to extract and identify novel chemical products produced by Arthrobacter sp. TAJX1902, particularly antimicrobial metabolites. Although underexplored, Arthrobacter sps. have been shown to produce bioactive compounds of great versatility; one such is a depsipeptide with quorum-sensing inhibitory activity.1 In this research, Arthrobacter sp. TAJX1902 isolated from a soil sample showed inhibitory activity against a filamentous indicator-type bacterium and a violacein-producing Janthinobacterium sp. A. sp. TAJX1902 was cultured using rich medium broth and agar and extracted with solvents of varying polarity. Characterization of purified bioactive compounds from A. sp. TAJX1902 was done via spectroscopic techniques, including 1D and 2D-NMR spectroscopy, FTIR, and GCMS analysis. The A. sp. TAJX1902 was found to produce pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(2-methylpropyl), and five other bioactive cyclic dipeptides (CDP)

Extraction, Purification, and Characterization of Potential Bioactive Compounds Produced by Janthinobacterium lividum TAJX1901

Underexplored environments such as soil samples continue to be an untapped source of bacterial strains with great potential to produce secondary metabolites for medicinal applications. As a result, these microorganisms represent a broad and yet unknown reservoir of new strains capable of producing these novel compounds. The current research primarily seeks to perform the isolation, purification, and characterization of secondary metabolites from a soil bacterium (Janthinobacterium lividum TAJX1901). The isolated soil bacterium was successfully cultured on rich media agar plates, followed by extraction using methanol and chloroform. The purification methods utilized include flash column chromatography, preparative thin-layer chromatography, and high-performance liquid chromatography. For structural elucidation, UV-Vis analysis, infrared spectroscopy, and nuclear magnetic resonance spectroscopy were employed. The extraction resulted in a dominant violet pigment soluble in methanol. Results revealed the presence of highly conjugated, polar, and aromatic compounds (violacein or relatives of violacein) and dioctyl phthalate (a contaminant)

Purification and Structural Elucidation of Bioactive Metabolites Isolated From Soil Bacterium Arthrobacter Sp. Strain TAJX1902

Arthrobacter belongs to an underexplored genus of antimicrobial-producing bacteria. All species in this genus are Gram-positive and commonly isolated from soil and marine sources. This genus is known to exhibit metabolic versatility greatly influenced by environmental conditions and nutrition. Arthrobacter sp. strain TAJX1902 isolated from an unknown soil sample is shown to inhibit a filamentous indicator type bacterium. It produced a few bioactive secondary metabolites in rich medium (RM) broth and agar culture. TAJX1902 crude extract was primarily fractionated using a Sephedex LH-20 column. Further purification achieved via Flash Column Chromatography and Preparative Thin layer Chromatography yielded five prominent crude products. The scope of this project is to fully determine the structure of potential novel antibacterial compounds from TAJX1902 via spectroscopic techniques including full 2D-NMR spectroscopic data set in combination with High-Resolution Mass Spectroscopy (HRMS). The research work is currently underway towards the final purification of the compounds using High-Performance Liquid Chromatography (HPLC) method to enable structural determination and evaluation of their antimicrobial activities

Extraction, Purification, and Characterization of Bioactive Compounds Produced by Janthinobacterium Lividum Strain TAJX1901

Unexplored environments such as soil samples continue to be an untapped source of bacterial strains with great potential to produce potent secondary metabolites for medicinal applications. As a result, these microorganisms represent a broad and yet unknown reservoir of new strains capable of producing novel natural compounds. Secondary metabolites isolated from microorganisms are currently being used in the production of several antibiotics. The current research primarily seeks to perform bioactivity-guided isolation, purification, and characterization of secondary metabolites from a soil bacterium (Janthinobacterium lividum strain TAJX1901). To achieve this objective, liquid-liquid extraction of a rich medium (RM) agar inoculated with the soil bacterium was performed using a solvent mixture of chloroform and methanol (1:3). The agar extract was fractionated by flash column chromatography using a gradient elution of ethyl acetate and petroleum ether. For purification purposes, the crude fractions were subjected to both analytical and preparative thin-layer chromatography with a further option of high-performance liquid chromatography (HPLC). We also intend to use spectroscopic techniques like two-dimensional (2D) nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) to investigate the chemical structure of the extracted pure compounds

Extraction, purification, and characterization of potential bioactive metabolites produced by Janthinobacterium lividum TAJX1901

Underexplored environments such as soil samples continue to be an untapped source of bacterial strains with great potential to produce potent secondary metabolites for medicinal applications. As a result, these microorganisms represent a broad and yet unknown reservoir of new strains capable of producing these novel natural compounds. Secondary metabolites from microorganisms have been used in antibiotic production, chemotherapy, immunosuppressants, and various industrial applications. The current research primarily seeks to perform the isolation, purification, and characterization of secondary metabolites from a soil bacterium (Janthinobacterium lividum TAJX1901). To achieve these objectives, the soil bacteria was successfully cultured on rich media agar plates followed by liquid–liquid extraction using a solvent mixture of methanol and chloroform(3:1). Various purification methods were utilized, including flash column chromatography, preparative thin layer chromatography, centrifugation, and high-performance liquid chromatography (HPLC ) using different column types and elution methods. For structural elucidation, UV/Vis analysis, infrared spectroscopy, and nuclear magnetic resonance spectroscopy were employed. The extraction resulted in a dominant violet pigment soluble in methanol. Preliminary results reveal the presence of highly conjugated, polar, and aromatic compounds. This work is relevant in the current global search for novel compounds for tackling antibiotic-resistant organisms and treating other diseases and infections