Studies on bioemulsifier production by Bacillus licheniformis PTCC 1595

Surfactants are amphipathic molecules which reduce surface and interfacial tensions and widely used in pharmaceutical, cosmetic, food and petroleum industries. Biosurfactants are the structurally diverse group of surface-active molecules synthesized by microorganisms. There are several advantages for biosurfactants in contrast with chemical surfactants, such as lower toxicity; higher biodegradability; better environmental compatibility; higher foaming; high selectivity and specific activity at extreme temperatures, pH, and the ability to be synthesized from renewable feed-stock. In the present study, the production of bioemulsifer by Bacillus licheniformis PTCC 1595 was studied. B. licheniformis was grown in the nutrient broth medium and bioemulsifer production was evaluated every 24 h by surface tension and emulsification index (E24). Then B. licheniformis PTCC 1595 was grown in nutrient broth with different conditions in order to get maximum production of bioemulsifer. The best culture mediumwas found to be nutrient broth medium supplemented with starch, Fe2+, Mn2+ and olive oil. After growing the bacteria, the microbial biomass was removed from the supernatant by acidic precipitation method. Its amphipathic structure was established by biochemical and spectroscopy methods and it was confirmed to be a lipopeptide structure

Study of aqueous extract of three medicinal plants on cell membrane–permeabilizing and their surface properties

The aim of this study was to evaluate the effect of aqueous extract of three medicinal plants, Artemisia dracunculus L, Cuminum cyminum L and Heracleum persicum Desf, which contain saponins on biological membrane. Also in this study, some of their physicochemical properties were studied. At the first step, the aqueous extract of the plants were prepared, using maceration and then the extracts were lyophilized. 0.2 ml of RBC was added to 0.2 ml of different concentrations of each extract in McIvan’sbuffer, and then incubated in two different times and temperatures. The absorbance of the samples was determined by UV spectrophotometer. Among the three studied extracts, A. dracunculus L showed thehighest hemolytic effect and the Heracleum persicum Desf showed the lowest one. The values of emulsification Index (E24) and foam formation activity (Fh) showed for each extract the properties of surface activity. Regarding the results of this study, when considering the health of consumer, the use of aqueous extract of H. persicum Desf, with low hemolytic effect is preferred in pharmaceutical preparation. But if the hemolytic effect were considered, the use of aqueous extract of A. dracunculus L, with great hemolythc effect in comparison to the two other extract, is preferred