The production of interfacial emulsions by bacterial isolates from diesel fuels

Four bacterial isolates from contaminated diesel fuels were tested for their ability to produce surface-active substances. One organism, identified as a Pseudomonas species, gave the highest activity, followed by a Bacillus sp. The Pseudomonas produced surfactant in the presence of mineral salts and glucose only, but the emulsifying activity increased dramatically on the addition of sterile diesel oil, producing levels similar to those quoted by other workers.