Research Highlights

doi:10.1038/nindia.2013.148 Published online 12 November 2013

Antibacterial from marine bug

Researchers have discovered that extracellular polymers secreted by a marine bacterium can inhibit the growth of bacterial biofilms that are known to cause about 65 per cent of all bacterial infections in humans .

The antibiofilm activity of extracellular polymeric substances (EPS) makes them promising antibacterial agents for therapeutic applications. EPS-secreting bacteria have been identified in different habitats. However, no previous studies had probed EPS-forming marine bacteria such as Oceanobacillus iheyensis.

To explore the antibiofilm activity of EPS from a marine bacterium, the researchers isolated O. iheyensis from a natural biofilm in a marine habitat. They cultured the marine bacterium and collected the released EPS. They then investigated the antibiofilm activity of the EPS against the biofilm-forming pathogenic bacterium Staphylococcus aureus.

Biofilm formation in S. aureus decreased significantly with increasing EPS concentration. The EPS inhibited biofilm formation in S. aureus by disrupting cell-to-cell attachment and interactions. The polysaccharides present in EPS mainly blocked biofilm formation by S. aureus.

The EPS showed shear thinning behaviour at both low and neutral pHs, making it a promising additive for the food industry. In addition, EPS yielded a clear solution in water, indicating its potential application as a bioemulsifier.

"The EPS may be explored as a drug in controlling detrimental infections caused by S. aureus," says Bhavanath Jha, a co-author of the study.


  1. Kavita, K. et al. Characterisation and anti-biofilm activity of extracellular polymeric substances from Oceanobacillus iheyensis. Carbohydr. Polymer 101, 29-35 (2014) | Article |