Physicochemical Characterization of Lipopetides Obtained From the Hydrocarbon‐Degrading Bacteria Arthrobacter crystallopoietes B14903

ABSTRACT

Biosurfactants present strong potential to replace petroleum‐based surfactants due to their amphiphilic structure, high surface activity, and broad applicability. In this sense, this study reports the physicochemical characterization of novel biosurfactants produced by the underexplored strain Arthrobacter crystallopoietes B14903. GC–MS analyses and FT‐IR spectroscopy suggested the presence of cyclic lipopeptides, structurally related to arthrofactin, syringopeptin, and syringomycin. These biosurfactants exhibited high emulsifying efficiency, with EI ₂₄ values up to 65% against hydrophobic substrates such as almond, olive, and motor oils. Purified biosurfactants effectively reduced water surface tension to 28 mN/m, showing a critical micelle concentration of approximately 900 mg/L and a C20 value of 125 mg/mL. Notably, surface tension remained stable at approximately 38–40 mN/m after exposure to temperatures ranging from 20°C to 100°C, pH values between 7 and 11, and salinity levels up to 20% (w/w) NaCl, with no statistically significant differences detected. Antimicrobial assays demonstrated no inhibitory effects on pathogenic microorganisms. Overall, these findings position A. crystallopoietes B14903 lipopeptides as efficient, stable, and environmentally compatible biosurfactants suitable for applications requiring strong surface activity without disrupting microbial communities.