Microbially produced surfactants have been studied for microbially enhanced oil recovery (MEOR)
and the bioremediation of hydrocarbons. However, most of these studies have used biosurfactants produced by
one of a small number of pure-culture microbes isolated in a laboratory. In previous work, we determined that
biosurfactant-producing microorganisms were naturally present at two hydrocarbon-impacted sites. In this
study, we examine the prevalence of biosurfactant producers in uncontaminated soils. Biosurfactant-producing
bacteria were found to constitute a significant proportion (up to 35%) of aerobic heterotrophs. Biosurfactant
producers were isolated. Isolates were identified primarily as strains of Bacillus and Pseudomonas.