Produção de biossurfactantes por Aspergillus fumigantus utilizando o sisal como substrato.

Abstract

The biosurfactants are surface active compounds, synthesized by various microorganisms and are receiving growing attention about advantages that have over chemical surfactants, such as biodegradability, low toxicity and low cost production from industrial waste sources. This study targeted to evaluate the production of biosurfactants by Aspergillus fumigatus from sisal broth (Agave sisalana) which was used as a carbon source. It was employed submerged fermentation for 192 hours period using the filamentous fungus Aspergillus fumigatus. Samples were collected every 24 hours after inoculation. We analyzed production through substrate consumption, biomass, Emulsification Index (EI), Stability after 24 hours and Emulsification Activity. We have obtained the best results at time of 144 hours fermentation, maintaining stability over 90% on acid pH value around 4.74, 17,65g.L-1 biomass and 1.70 Emulsification Activity Units. In the factorial design 2², with triplicate at the midpoint, were analyzed the variables temperature (4°C, 30°C, 45°C) and salinity (0%, 5%, 10%) in the presence of diesel and kerosene after 60 minutes on the EI behavior. The results showed that in the presence of diesel none of the evaluated parameters influenced the IE behavior, and Experimental 2 and 4 obtained the best results in the presence of kerosene, and found that in tests with kerosene temperature was the factor that influenced in EI behavior. Consequently, the results indicate that sisal broth is a suitable substrate for biosurfactant production from Aspergillus fumigatus displaying potential to application on industrial and environmental processes.