Isolamento e Caracterização de Bactérias do Lodo de Esgoto com Potencial Antagonismo a NematóidesIsolation and Characterization of Bacteria from Sewage Sludge, with Potential Antagonism to Nematodes

Resumo

Foram isoladas e caracterizadas bactérias presentes no lodo de esgoto visando à realização de estudos futuros de interação desses organismos com fi tonematóides. Os lodos utilizados são provenientes das estações de tratamento de Franca e Barueri, no Estado de São Paulo. Foram obtidos 77 isolados do lodo de Franca e 143 do de Barueri. Desses isolados de Franca testados, 77% foram Gram-positivos e 23% Gram-negativos. Para os 143 isolados obtidos do lodo de esgoto de Barueri, 61% foram Gram-positivos e o restante Gram-negativo. Os isolados Gram-positivos podem, estar relacionados com espécies do gênero Bacillus dos quais várias espécies têm grande importância como agentes de controle de fi topatógenos, inclusive nematóides. Observou-se que 39% e 40% dos microrganismos Gram positivos, isolados dos lodos coletados na ETE de Franca e de Barueri, produziram pigmento fluorescente em meio King B, sendo indicativo de Pseudomonas fluorescens. Dos 77 isolados de Franca, 13% apresentaram como característica morfológica bordo lobado, característica de culturas de Bacillus. Comparando-os com os testes bioquímicos, concluiu-se que 80% deles foram Grampositivos, característica de espécies de Bacillus. Dos isolados, 10% apresentaram bordo inteiro, colônia brilhante e arredondada, as quais são características de Pseudomonas. Desses, 37% foram Gram-negativos, sendo que 67% desses isolados eram também produtores de pigmento fluorescente em meio King B, características da P. fluorescens. Dos 143 isolados de Barueri, 17% apresentaram bordo lobado como característica morfológica, podendo-se suspeitar de serem espécies de Bacillus e 5% apresentaram as características de espécies de Pseudomonas. Para os isolados do lodo de Barueri, na comparação com os testes bioquímicos constatou-se que 64% dos isolados foram Gram-positivo. Dos isolados com características de Pseudomonas, 17% apresentaram-se como Gramnegativas e desses, 17% mostraram-se como produtores de pigmento fluorescente em meio King B, que são características de espécies de Pseudomonas do grupo fluorescente.

Summary

This work aimed at isolating and characterizing bacteria presented in sewage sludge with the objective of future studies for the interaction of these organisms with nematodes. For this study, it was used samples of the sewage sludge originated from the treatment stations of the cities of Franca and Barueri, in the state of São Paulo. It was obtained 77 samples of isolated sewage sludge from Franca and 143 from Barueri. From the Franca samples, 77% was Gram-positive and 23% was Gram-negative while from the Barueri samples, 61% was Gram-positive and the rest was Gram-negative. The isolated Gram-positive can be related to the species of the genre Bacillus, whose species have great importance as agents of the phytopathogens control, including nematodes. It was observed that 39% and 40% of the Gram-positive microorganisms isolated from the collected sewage sludge in ETE from Franca and from Barueri produced fluorescent pigments in King B medium, as indicative of Pseudomonas fluorescent presence. By examining the 77 samples of sewage sludge from Franca, 13% presented as morphologic characteristic, the margin of lobes, characteristic of the Bacillus culture. When compared them to the biochemistry tests, it was concluded that 80% was Gram-positive, a characteristic of the Bacillus species. By isolating the samples of sewage sludge from Franca, 10% presented whole margin, fluorescent and round colony, characteristics of the Pseudomonas while 37% was Gram-negative, considering that 67% of this isolated sewage sludge produced fluorescent pigments in King B medium, characteristics of Pseudomonas fluorescence. By examining the 143 samples of sewage sludge from Barueri, 17% presented the margin of lobes, as a morphologic characteristic, suggesting that they belonged to the Bacillus species and 5% presented the characteristic of the Pseudomonas species. By isolating the samples of sewage sludge from Barueri, it was found out, during the comparison with the biochemistry tests, that 64% was Gram-positive. From the isolated sewage sludge that presented the Pseudomonas characteristics, 17% indicated to be Gram-negative while 17% demonstrated to be producers of fl uorescent pigments in King B medium, characteristics of the Pseudomonas species from the fluorescent group.