Biosurfactant from Candida guilliermondii UCP 1592 for cleaning and degreasing applications

Biosurfactants are surface-active molecules produced by microorganisms, whose amphiphilic structure enables them to reduce surface tension and stabilize emulsions. This study evaluated the production, characterization, stability, toxicity, and cleaning potential of a biosurfactant synthesized by Candida guilliermondii UCP 1592. The compound was produced in a medium containing distilled water, 2.5% corn steep liquor, and 5% residual frying oil, under agitation for 144 h. The biosurfactant reduced the surface tension of water from 72 to 30 mN/m and achieved a production yield of 18 g/L. It effectively emulsified 100% of burnt motor oil, forming a stable emulsion. Toxicity tests using Tenebrio molitor and Artemia salina revealed no toxic effects, with 100% survival. In cleaning tests, the biosurfactant removed 100% of oil from glass surfaces, even at concentrations below its critical micelle concentration (CMC). For oil removal from cotton fabrics, it reached efficiencies of 91, 70, and 57% at 2 CMC (0.6 g/L), 1 CMC (0.3 g/L), and 0.5 CMC (0.15 g/L), respectively. These results demonstrate the biosurfactant’s high effectiveness, safety, and environmental compatibility, highlighting its potential as a sustainable alternative to synthetic surfactants for cleaning and oil removal applications.