Characterization of a lipopeptide biosurfactant produced by a crude-oil-emulsifying Bacillus sp. I-15

► Isolation of a crude oil-emulsifying Bacillus sp. I-15. ► Growth-associated biosurfactant production from glucose. ► Morphological and physiological changes due to biosurfactant production. ► Microheterogeneity in 16S rDNA genes.