Microbial functional groups in soils contaminated with toxaphene in the department of Cesar, Colombia

Abstract

Toxaphene is an organochlorine pesticide that was used for years in the cultivation of cotton. After its prohibition in the old cellars of Cenalgodon (Caracolicito - Cesar), bad management practices were carried out that generated soil contamination. Due to this problem, and to the well-recognized importance of the functional microbial groups as quality indicators, a soil analysis was performed in contaminated and uncontaminated soils to evaluate the effect of toxaphene on some microbial communities during two climatic periods. Some populations of cultivable microorganisms related to the carbon and nitrogen cycles were evaluated by the method of direct plate count and most probable number using selective culture media. The total counts of the population of bacteria, fungi (Log CFU / g of soil) and microbial functional groups of C and N (Log NMP / g of soil) isolated from the soil contaminated with toxaphene were lower than those recorded for the control soil during the drought and rain periods (p.0.05). Some groups of microorganisms were correlated positively for both soils indicating their synergistic participation in the cycling of nutrients, which could favor the recovery of contaminated soil and the maintenance of the ecosystem as long as the environmental and the physicochemical conditions of the system are improved.