Production and Characterization of Surface‐Active Lipopeptides by Haloalkaliphilic Bacteria Salibacterium sp. 4CTb

Abstract

AbstractSurface‐Active Biomolecules (SAB) obtained from microbial sources are safe alternatives to chemically synthesized counterparts for many environmental and industrial applications. These applications frequently involve the exposure of the SAB to extreme factors making necessary to seek for molecules that are able to function under such conditions. In this work, the polyextremophilic bacterium Salibacterium sp. 4CTb is reported as a SAB producer. Its emulsifier activity increased almost twofold when the C/N ratio and culture conditions were modified. The partially purified molecule was able to form stable emulsions under extreme conditions (70 °C, pH 12, and 4 M NaCl) better than other commercial molecules, and reduced the surface tension of the water to 49.78 mN m−1 with critical micelle concentration (CMC) of 15.1 mg L−1. Carbohydrate, lipid, and protein assays, accompanied by the Fourier Transform Infra‐Red (FTIR) and electrospray ionization mass spectroscopy (ESI‐MS) results, indicate the lipopeptide nature of the compound with masses around 645 and 746 Da. The SAB obtained from Salibacterium sp. 4CTb may be suitable for electrical, food, pharmaceutical and cosmetic industries, agriculture, and environmental applications, among others.