Production of surfactin by Bacillus subtilis LAMI005 and evaluation of its potential as tensoactive and emulsifier

Abstract

AbstractIn this study, the kinetic of lipopeptide biosurfactant production by Bacillus subtilis LAMI005 and its tensoactive and emulsifier properties were evaluated. The influence of the concentrations of nitrogen ((NH4)2SO4) and carbon source (glucose and fructose) on biosurfactant production, using a mineral medium, were evaluated. A production of about 930 mg · L−1 of surfactin was observed for mineral medium supplied with total reducing sugars (16.55 g · L−1) and (NH4)2SO4 (1 g · L−1) as carbon and nitrogen sources, respectively. The crude biosurfactant exhibited its potential as tensoactive, presenting the capability to reach surface tension of about 28 mN ⋅ m−1 for water and exhibiting low CMC (~14–20 mg · L−1). The analysis of emulsifying activity showed a greater stability of emulsion formed in motor oil (3.5 U), soybean oil (2.0 U), and biodiesel (1.5 U). The emulsion formulated on motor oil remained stable for more than 200 h, which was explained by its average drop diameter (~0–10 μm). The surface‐active properties of surfactin did not seem to be affected by different NaCl concentrations, which may promote its applicability in high salt environments, such as oil spills in marine areas.