Preliminary characterization of exopolysaccharides produced by a marine biofilm-forming bacterium Pseudoalteromonas ruthenica (SBT 033)

Aim: The major objective of the present study was the partial characterization of the exopolysaccharides (EPS) produced by a marine biofilm-forming bacterium Pseudoalteromonas ruthenica under shake culture conditions. Methods and Results: EPS-producing bacterial cultures were isolated from the sea water collected from the vicinity of coastal electric power station. Zobell marine broth medium was used for growth of the cultures and the EPS produced was quantified using phenol sulfuric acid method. Chemical characterization of the EPS was carried out using Fourier transform infrared spectroscopy (FTIR), and capillary gas chromatography (GC). Further, viscosity and rheological properties of the purified EPS were studied. The FTIR spectrum revealed prominent peaks of various groups of OH and CH3 bending. GC analysis showed the presence of eight individual sugars. Rheological studies of the aqueous EPS showed good shearing property. Conclusions: Pseudoalteromonas ruthenica isolated from marine environment produced copious amount of EPS under shake culture conditions. GC analysis of the EPS revealed the presence of eight individual sugars and the EPS had good shearing property. Significance and Impact of the Study: The EPS produced by P. ruthenica is pseudoplastic in nature and is stable at higher pH levels. These properties suggest that the EPS may have potential applications in the oil, textiles and food industries.