Tiago Silva / LNEG- Laboratório Nacional de Energia e Geologia / Portugal
T.P. SILVA / LNEG- LABORATÓRIO NACIONAL DE ENERGIA E GEOLOGIA / PORTUGAL
S.M. PAIXÃO / LNEG- LABORATÓRIO NACIONAL DE ENERGIA E GEOLOGIA / PORTUGAL
J. TAVARES / LNEG- LABORATÓRIO NACIONAL DE ENERGIA E GEOLOGIA / PORTUGAL
L. ALVES / LNEG- LABORATÓRIO NACIONAL DE ENERGIA E GEOLOGIA / PORTUGAL
Biosurfactants are surface active compounds, possessing both hydrophilic and hydrophobic properties, which allow them to reduce the surface tension between two immiscible liquids, such as water and oil. These compounds have gained the interest of many industries, due to their characteristics, such as, biodegradability, low toxicity, and antibiotic and antioxidant activities. Thus, they are now seen as added-value byproducts, which should be valued in a biorefinery setting. Gordonia alkanivorans strain 1B is a biodesulfurizing bacterium that naturally produces biosurfactants, however there is still very little information on how they are produced and their properties. In this work, different carbon sources were used to grow the bacterium and induce biosurfactant production. The results showed that, even without the use of hydrophobic inducers strain 1B could produce a crude extract with both biosurfactant and bioemulsifier activities. It was clear that, the different inducers not only affected the amount of surfactant produced, but also its properties. When using olive oil as an inducer, the surfactant mostly acted on the hydrophobic layer, and when using sucrose, or a complex culture medium, such as Yeast Malt Broth, the surfactant affected mainly the aqueous layer. This reinforces the importance of studying induction conditions, since different properties can lead to different applications.
This work was financed by national funds through FCT (Fundação para a Ciência e a Tecnologia) in the scope of the project GreenFuel (PTDC/EAM-AMB/30975/2017). In addition, this research was carried out within the Biomass and Bioenergy Research Infrastructure (BBRI) - LISBOA-01-0145-FEDER-022059, supported by Operational Programme for Competitiveness and Internationalization (P2020), by Lisbon Portugal Regional Operational Programme (Lisboa 2020) and by North Portugal Regional Operational Programme (Norte 2020) under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Tiago P. Silva also acknowledges FCT for his PhD financial support (SFRH/BD/104977/2014).