Fig. 2
Stability studies for biosurfactants produced by Bacillus atrophaeus 5-2a in ‘BB’ and ‘BU’ media, under different conditions of temperature (a), pH (b), and salinity (c). Values represented the mean ± standard deviation (n = 3). D for oil spreading (cm); E24 for emulsification index (%); and ST for surface tension (mN m−1)