Fig. 2. Surface tension on actinomycetes isolates growing on glycerol, n-hexane and molase substrate media
The resulting free cell supernatant is measured by its surface tension value using a Du Nouy tensiometer at room temperature. The results of surface tension measurements and a decrease in the value of the surface tension to the control can be seen in Fig 2. The value of the surface tension measured at day 0 (control) and day 7). The decrease in surface tension is caused by the presence of biosurfactants in the supernatant produced by bacterial isolates during the growth process.