| dc.description.abstract | Surfactants are amphipathic molecules of microbial origin that exhibit activity on different types of surfaces, have high biodegradability, low toxicity, can be produced from renewable sources and have funcionality under extreme conditions of pH and temperature. Oleaginous microorganisms present as main characteristic the ability to accumulate lipids over 20% of its dry weight, represented in the form of triacylglycerol, a constitution comparable to vegetable and animal oils, and their chemical composition similar to biodiesel. Assays were carried out for the simultaneous production of lipids and biosurfactant by Penicillium spinulosum UCP1347 using as substrates corn steep liquor (5%) and post-frying soybean oil (3%), using an Experimental Design - Central Composite Design CCD 22. The fermentation was performed in Erlenmyers flaks containing 100 mL of medium, in according to the CCD, 5% of the suspension inoculum of 107 spores/mL, incubated at temperature of 28°C, orbital shaking of 150 rpm and 96 hours. At the end of fermentation, the cell free broth showed the production of a biosurfactant, which reduced the water surface tension from 72 to 32.7 mN/m, interfacial tension of 1.7 mN/m, CMC 1.25% (w/v), emulsifying activity 3.73 UEA /mL using post-frying soybean oil, as well as stability against pH, temperature and salinity. The anionic character of biosurfactant showed a polymeric composition (39.56% carbohydrates, 33.78% lipids and 10.4% protein). In the same assay (central points) was observed accumulation of a biomass with 57% of lipids in the dry weight, with a chemical composition of unsaturated fatty acids (palmitoleic, oleic and linoleic acids) and saturated (palmitic and stearic acids). The results show that P. spinulosum is an oleaginous filamentous fungus, promising with high biotechnological potential in the production of biosurfactant and lipids to the biodiesel formation and the ability to use agro-industrial waste as alternative and renewable sources, reducing the production costs of both products. | eng |
