Bactérias isoladas de solos rizosféricos de Allium fistollium L. com histórico de aplicação do fungicida mancozeb na comunidade Nova Esperança Manaus-AM.

Abstract

The utilization of pesticides in agriculture has been intensified, causing big impact in the soils and biota. The presence of these compounds in soils has been resulting in microorganism behavior modification, developing survival strategies to the presence of these products. The Manconzeb is a carbamate`s fungicides group that acts, inactivating the essential enzymes of fungi. The subjects of this study were: to characterize chemically and physically rhizosphere soil samples with history of repeated fungicide application; to isolate bacteria from this soil; to characterize the isolates with biochemical tests and molecular tools; to obtain the growth of the isolates in environment with the fungicide; to establish a bacterial collection with bioremediation potential. Samples of soils were collected and it was determined their chemical and physical characteristic. The bacterias were isolated using two different techniques: minimal salt broth, and Busheel Haas broth containing 3,6gL-1of Mancozeb. The isolated strains were submitted to tests in minimal salt broth to evaluate the potential of degradation in environment with this fungicide. The identification was made through the phenotypic characterization, using biochemical tests to determine the gender and molecular identification using the sequencing of the region 16S, with the primers 1492R, 513F with amplification of 1000 pb. The 23 bacterial isolates were identified as 4 families, 4 genders and 11 species. The Bacillaceae family is more representative with 86,95% of the isolates. These tests provided to verify the tolerance of the bacteria that was isolated in higher concentrations of Mancozeb that are used in field to control pests. The collection of microorganisms resulting from this research may contribute for future studies involving the biodegradation of xenobiotics.