Tuesday, April 30, 2013
Exhibit Hall
Biosurfactants of microbial origin are compounds which exhibit surfactant properties, and consist of metabolic by-products of bacteria, fungi and yeasts. Such products can be used in various applications such as bioremediation of hydrocarbons, in agriculture, food industry, pharmaceutical, cosmetics and others. They have ecological, economic and social benefits, since they are biodegradable and non-toxic to the environment. Furthermore, they have the ability to remain stable under extreme conditions of pH, temperature and salinity. In the present study, strains of microorganisms that were previously identified as being gene positive for surfactin production were investigated. These strains were isolated from mangroves of Ceará – Brazil and named ICA 24 and ICA 56. Growth and surface tension reduction was observed for both microorganisms investigated. The surface tension of the fermented broth free of cells was reduced to 29.25 ± 0.4 dyne/cm (ICA 24) and 29.75 ± 1.1 24 dyne/cm (ICA 56). It is known that a criterion for selecting biosurfactant producing microorganisms is their ability to reduce surface tension. Surfactin, for instance, a well-known biosurfactant, can decrease the surface tension of water from 72dina/cm to 27.9 dyne/cm when present at the concentration of 0.005%. These results indicate that ICA 24 and ICA 56 are promising strains for biosurfactant production.