Fig. 6

Emulsification activity associated with P. septica isolates OOWS-10. a Behaviors of P. septica OOWS-10 and OOYS-10 in an olive oil–water mixture. Note the tendency of P. septica OOWS-10 to form clusters at the interface of the oil–water mixture. The white bars represent 10 μm. b Emulsification activity assay. P. septica OOWS-10 and OOYS-10 were grown to confluence on LB agar, harvested and resuspended in PBS. Bacteria were removed by centrifugation and equal volume of bacteria supernatants and diesel fuel containing the lipophilic dye Sudan Black were then mixed, and allowed to separate in a test tube. E. coli strain FB8 was used as a negative control