Publications by authors named "C Sivapathasekaran"

The extracellular biosurfactant product secreted by a marine bacterium was concentrated and purified directly from the fermentation broth in a single step by ultrafiltration (UF) employing YM 30 kDa (UF-I) and Omega 10 kDa (UF-II) polyethersulfone membranes. The optimum operating pressure required for both membranes, UF-I and UF-II, were found to be 30 and 35 psi, respectively. The biosurfactant from the fermentation broth was recovered in higher amounts using UF-II (89%) than using UF-I (73%).

View Article and Find Full Text PDF

A combinatorial screening strategy was adopted for the development of a suitable medium for enhanced biosurfactant production by a marine strain. As a result, a modified marine medium (MMM) was developed, which contained urea and strontium chloride besides other salts important for the growth of marine bacteria. This medium supported growth, evident from a higher maximum growth rate value of 0.

View Article and Find Full Text PDF

Marine environment occupies the vast majority of the earth's surface and is a rich source of highly potent and active compounds. In recent years, microbial surfactants and emulsifiers have been reported from marine microflora. Surfactant and emulsifier molecules having diverse chemical nature such as exopolysaccharides, carbohydrate-lipid-protein complexes or glycolipopeptide, glycolipids, lipopeptides, phospholipids and ornithine lipids have been reported from various marine bacteria.

View Article and Find Full Text PDF

A nonlinear model describing the relationship between the biosurfactant concentration as a process output and the critical medium components as the independent variables was developed by artificial neural network modeling. The model was optimized for the maximum biosurfactant production by using genetic algorithm. Based on a single-factor-at-a-time optimization strategy, the critical medium components were found to be glucose, urea, SrCl(2) and MgSO(4).

View Article and Find Full Text PDF

A marine Bacillus strain produced biosurfactant during its growth in a defined glucose-containing medium. An efficient method for separation and purification of biosurfactant isoforms was developed and optimized in high-performance liquid chromatography (HPLC) by manipulating solvent gradient program and flow rates. Starting with an initial run time of 60 min, the final optimized method had a significantly reduced run time of 20 min.

View Article and Find Full Text PDF