title: The sponge-associated bacterium Bacillus licheniformis SAB1: a source of antimicrobial compounds.
abstract: Several bacterial cultures were isolated from sponge Halichondria sp., collected from the Gujarat coast of the Indo Pacific region. These bacterial cultures were fermented in the laboratory (100 mL) and the culture filtrate was assayed for antibiotic activity against 16 strains of clinical pathogens. Bacillus sp. (SAB1), the most potent of them and antagonistic to several clinically pathogenic Gram-positive, Gram-negative bacteria and the fungus Aspergillus fumigatus was chosen for further investigation. Analysis of the nucleotide sequence of the 16S rDNA gene of Bacillus sp. SAB1 showed a strong similarity (100%) with the 16S rDNA gene of Bacillus licheniformis HNL09. The bioactive compounds produced by Bacillus licheniformis SAB1 (GenBank accession number: DQ071568) were identified as indole (1), 3-phenylpropionic acid (2) and a dimer 4,4'-oxybis[3-phenylpropionic acid] (3) on the basis of their Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR) and Electrospray Ionization Mass Spectrometer (ESI-MS) data. There is a single reference on the natural occurrence of compound 3 from the leaves of a terrestrial herb Aptenia cordifolia in the literature, so to the best of our knowledge, this is a first report of its natural occurrence from a marine source. The recovery of bacterial strains with antimicrobial activity suggests that marine-invertebrates remain a rich source for the isolation of culturable isolates capable of producing novel bioactive secondary metabolites.
authors.affiliation: Bioorganic Chemistry Laboratory, Chemical Oceanography Division, National Institute of Oceanography, Council of Scientific and Industrial Research, Dona Paula 403004, Goa, India. dprabha@nio.org
authors.forename: Prabha
authors.initials: P
authors.lastname: Devi
authors.forename: Solimabi
authors.initials: S
authors.lastname: Wahidullah
authors.forename: Cheryl
authors.initials: C
authors.lastname: Rodrigues
authors.forename: Lisette D
authors.initials: LD
authors.lastname: Souza
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001407:Bacillus / Q000737:chemistry* / Q000302:isolation & purification; D007194:India; D019156:Indian Ocean; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010140:Pacific Ocean; D011161:Porifera / Q000382:microbiology*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000890:Anti-Infective Agents