Strategy for Bioremediation of Unsaturated Soil Without a History of Paclobutrazol Application

The biodegradation of paclobutrazol (PBZ) was evaluated during 49 days using glycerol and agro-industrial wastes (biodiesel-derived glycerol, peanut cake and sesame cake) as additional carbon sources and unsaturated soil with a history of PBZ application. Biodiesel-derived peanut cake was the best agro-industrial waste, and this was used in the following four strategies. Four biodegradation strategies were performed using 100, 80, 50 and 20 % of soil without history with the addition of 0, 20, 50 and 80 % of soil with history, respectively. The addition of soil with history (50 or 80 %) and the selected waste (peanut cake) favored biodegradation of soil without history, with rates about 95 %. The peanut cake waste proved to be an adequate source of carbon and nitrogen, and the soil with history, proved to be an efficient reservoir of microorganisms capable of biodegrading PBZ.