Assessing the impact of biosurfactants extracted from corn steep liquor at pilot scale on water suspensibility of metallic biocides

BACKGROUND: Corn steep liquor (CSL) is a rich source of bioactive compounds, particularly biosurfactants. In this work, two biosurfactant extracts were produced successfully at a pilot scale using CSL. One was more hydrophobic and was obtained through liquid-liquid extraction with ethyl acetate (BS-ACT). The other was more hydrophilic, obtained through solid-liquid extraction with phosphate buffer saline (PBS) (BS-PBS). RESULTS: The biosurfactant extracts (BS-ACT and BS-PBS) were included in biocide formulations to assess their impact on enhancing the suspensibility and solubility of different metallic active substances. The BS-PBS extract exhibited superior properties in suspending biocides in comparison with BS-ACT, despite BS-ACT demonstrating a higher solubility capacity. Moreover, in comparison with chemical surfactants, BS-ACT displayed significantly greater ability to solubilize biocides in water, whereas BS-PBS showed suspensibility results that were comparable with synthetic surfactants. CONCLUSION: Biosurfactant extracts derived from CSL act as coadjutants in metallic biocide formulations, enhancing their dissolution or suspension in water and providing a sustainable alternative to chemical surfactants.