Pilot plant study of the microbial flora in a diesel fuel contaminated soil

This study focused on the impact of a recent soil pollution of diesel fuel on a site and its indigenous microbial flora. A pilot plant (0.5 m(3)) was set up and filled with a soil (about 700 kg), artificially and uniformly po lluted with diesel fuel (7 g/kg). This plant was then chemically and biolog ically monitored during the whole experiment (about two years). During the monitoring, a morphological change of the microbial colonies was observed. This was probably due to the acclimation phenomena to the pollution. With b atch kinetic studies (10 ml) and increasing the selective pressure of the p ollutant, it was possible to select and isolate a microbial consortium and a single strain that developed the ability to use different diesel fuel fra ctions as carbon sources. GC-MS analytical techniques were used. Results sh owed that different fractions were degraded at different times. In the batc h system, in 7 days, the microbial consortium degraded some aromatic hydroc arbons. The isolate strain, in 20 days, degraded linear hydrocarbons. After a two years acclimation, it was possible to obtain, from a pilot plant, a microbial consortium and a strain able to degrade diesel fuel, for a future bioremediation in situ process.