Evaluación de la actividad enzimática de hongos y bacterias procedentes de un suelo agrícola contaminado con plaguicidas de la Parroquia San Luis para la elección del microorganismo más eficiente para su biorremediación.

Abstract

The objective was to evaluate the enzymatic activity of fungi and bacteria from an agricultural soil contaminated with pesticides, from the San Luis parish, for the choosing the most efficient microorganism for its bioremediation. This enzymatic activity was evaluated in 132 isolations obtained from the soil samples of the study site, by comparing the amylolytic, lignocellulolytic and casein degradation activity. Additionally, biochemical identification tests were performed to understand other enzymatic complexes that could be important. In addition, the direct incidence of pesticides (Rugby, Tryclan + Sharfip) frequently used in agricultural cycles was tested to see their direct influence on the growth and morphology of the colony and finally with these results to establish the efficient microorganism with potential for bioremediation. The results showed that 80% of the total isolates were effective for amylolitic activity, 50% showed lignocellulolytic activity and only 25% were able to degrade casein. The statistical analysis then showed a highly significant difference for enzymatic activity with p <0.05. The direct influence of the insecticides on the microbial morpho-physiology revealed that Rugby affects 99.2% of the isolates, while the mixture (Tryclan + Sharfip) did not affect 61.4% of isolates, 33.3% were somehow altered in their morphology and only 5.3% was affected. Under this context, the actinomycete DCB3025 and fungi DCB 3007,3010, 3019, 3031 and 3043 were the most efficient for the objectives proposed in this work, this is why it is recommended to use them as potential bioremediators in sources contaminated with pesticides or other materials used in agricultural production.