Production and properties of a bioemulsifier obtained from a lactic acid bacterium

GIANNI DE CARVALHO, K.; GÓMEZ, J.E.; VALLEJO, M.; MARGUET, E.R.; PEROTI, N.I.; DONATO, M.; ITRI, R.; COLIN, V.L.

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2019 vol. 183

0147-6513

In the present work, the production of bioemulsifier (BE) by a lactic acid bacterium (LAB) grown at 25 °C in lacticwhey-based media for 24 h was evaluated. Maximum production was detected in a medium containing yeastextract, peptone and lactic whey (LAPLW medium), with a yield of 270 mg L−1. The BE proved to be moreinnocuous for Caco-2 cells, used as a toxicological indicator, than the non-ionic surfactant Triton X-100. Inaddition, the microbial product presented higher stability to changes in temperature (37 °C to 100 °C), pH(2?10), and salt concentration (5% and 20%, w/v) than the synthetic surfactant. Regarding emulsifying capacitytested against different hydrophobic substrates (kerosene, motor oil, diesel, sunflower oil, and grape oil), the BEdisplayed E24 values similar to or even better than those of Triton X-100. Finally, Triton X-100 caused irreversible modifications on the giant unilamellar vesicles (used as model membrane system), promoting the solubilization of the lipid bilayers. Nevertheless, BE induced temporary modifications of the membrane, which isassociated with incorporation of the bioproduct in the outer layer. These results demonstrate the role of BE inbiological processes, including reversible changes in microbial membranes to enhance the access to hydrophobicsubstrates.