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.

Syntheses and biological activities of the proposed structure of apteniol A and its derivatives

“…Devi et al have also reported an isolation of apteniol A from the marine bacterium Bacillus licheniformis SAB1 as an antimicrobial metabolite. 3) However, the 1 H-and 13 C-NMR data provided by these reports did not agree with each other. Therefore, to solve this contradiction, we synthesized the proposed apteniol A.…”

Mini-review: Inhibition of biofouling by marine microorganisms

“…Three antibacterial compounds were isolated from methanol extracts of the bacterium Bacillus licheniformis associated with the sponge Halichondria sp. (Table 1; Devi et al 2010). One of these compounds, indole, had significant activity against bacterial pathogens, while others, 3-phenylpropionic acid and 4,4′-oxybis[3-phenylpropionic acid], had moderate and weak antibacterial activity, respectively.…”

“…For example, indole is involved in the formation of biofilms by V. cholerae (Mueller et al 2009) and has significant activity against bacterial pathogens (Devi et al 2010). DKPs produced by many bacteria can work as signal molecules (Tommonaro et al 2012), inhibit the formation of biofilms (de Carvalho & Abraham 2012), the growth of bacteria ) and the settlement of larvae Qi, Xu, Gao et al 2009).…”

Diversity and Bioactivity of Marine Bacteria Associated with the Sponges Candidaspongia flabellata and Rhopaloeides odorabile from the Great Barrier Reef in Australia

“…The liquid fermentation medium was then centrifuged at 7000× g for 20 min [18] to obtain the cell-free supernatant (CFS). The CFSs were then extracted twice with ethyl acetate (EtOAc, Honeywell Research Chemicals) [18,38] and the organic phase was evaporated to dryness on a rotary evaporator (BÜCHI™ Rotavapor R-205) at 37 • C to obtain a crude extract [11,[39][40][41]. In this instance, bioactivity was tested using the method by Dashti, et al [42].…”