A comparative study was carried out on the production of exopolysaccharides (EPS) at the laboratory scale. EPS was produced from P. aeruginosa, P. fluorescens and Bacillus species. EPS was obtained by ethanol precipitation method and the total carbohydrate content was determined. The major sugar unit was found to be glucose using Thin Layer Chromatography (TLC). The functional groups were identified using FTIR spectroscopy. The production of EPS was noted to be higher during its stationary phase of growth. The maximum yield of EPS, by batch studies, was found to be produced by Bacillus sp. (1,352 mg/L), followed by P. aeruginosa (1,302 mg/L) and P. fluorescens (1,285 mg/L).

Microbes release polysaccharides extracellularly as exopolysaccharides (EPS) in the environment, in the form of capsules or slime (Aung et al., 2008). Recent researches are carried out on the production of EPS, for they are biologically essential and degradable polymers. EPS are found to be produced by bacteria, fungi, actinomycetes (Usama et al., 2009; Chunhui et al., 2010; and Rong et al., 2010). EPS are highly important to any bacterium as a defense mechanism and for adhesion (Francis et al., 2009), in industries as gelling agents, biosurfactants, emulsifiers, viscosifiers (Barbara et al., 1986; Annarita et al., 2010; and Surekha et al., 2010), as biosorbents (Paula et al., 2008; and Xavier et al., 2009) and biologically active as antimicrobials, anticancer agents, antioxidants (Dilsad and Belma, 2008; Li et al., 2009; Jun et al., 2010; Kanokarn et al., 2010; and Chu-Ting et al., 2011).

Biotechnology Journal, Stress Adaptation of Bacteria, Extremophiles, Bacterial Adaptation, Cytosolic Components, Denature Cellular Proteins, Reactive Oxygen Species, Monounsaturated Fatty Acids, Ultraviolet Radiation, Environmental Stress, Stress Management, Biological Systems, Cellular Economy.