| Summary: | A presen?a natural do enxofre no meio ambiente e nos combust?veis f?sseis justifica a ocorr?ncia tanto de esp?cies bacterianas, quanto de genes espec?ficos, associados ao processo de biodessulfuriza??o. Esta tecnologia, baseada no metabolismo dos microrganismos, consiste na retirada do enxofre presente nas cadeias dos hidrocarbonetos arom?ticos polic?clicos (PAH?s), visando minimizar as emiss?es de ?xidos sulfurosos na atmosfera, no processo de refino, al?m de evitar a forma??o e precipita??o da chuva ?cida no meio ambiente. Este trabalho teve como objetivo investigar a presen?a dos microrganismos dessulfurizadores, a partir de amostras de solos rizosf?ricos e n?o-rizosf?ricos, contaminados com petr?leo e n?o-contaminados e em solos oligotr?ficos coletadas no Continente Ant?rtico. Para isso, foram obtidos isolados bacterianos os quais foram submetidos a testes de capacidade de dessulfuriza??o, em fun??o da forma??o do produto final do metabolismo microbiano, o 2-hidroxibifenil, evidenciando a cin?tica do processo de dessulfuriza??o do dibenzotiofeno atrav?s de t?cnicas espectrofotom?tricas. Al?m disso, tamb?m foram utilizadas t?cnicas moleculares de extra??o de DNA, BOX-PCR e sequenciamento de DNA, no intuito de se obter um perfil gen?mico e filogen?tico da comunidade microbiana cultiv?vel presente nestas amostras. Deste modo, foram obtidos 50 isolados com capacidade de utilizar o dibenzotiofeno como fonte energ?tica, independente da rota metab?lica, sendo que a maioria apresentou forma de cocos (68%) com colora??o Gram-positiva (44%). Ap?s a sele??o dos isolados, atrav?s do ensaio de Gibb?s, obteve-se 7 isolados com metabolismo de dessulfuriza??o, sendo que a partir da curva de crescimento, em fun??o da forma??o do 2-hidroxibifenil, verificou-se que uma estirpe possu?a altos ?ndices de dessulfuriza??o, em rela??o aos demais isolados. O sequenciamento revelou que os 7 isolados pertencem aos g?neros Acinetobacter sp., Pseudomonas sp., e ? esp?cie Pseudomonas corrugata. The presence of sulfur in nthe natural environment and fossil fuels justifies the occurrence of both species, and specific genes involved in the process of biodesulfurization. This technology, based on the metabolism of microorganisms, consists of removing the sulfur present in chains of polycyclic aromatic hydrocarbons (PAH's) to minimize emissions of sulfur oxides in the atmosphere, in the refining, and prevent the formation and precipitation of acid rain in the environment. This work aimed to investigate the occurence the microorganisms with desulfurization ability, from samples of soil collected from the Antarctic Continent. For this reason was tested the growth of selected isolates with desulfurization capacity, due to the formation of the end product of microbial metabolism, 2-hydroxibifenyl, showing the kinetics of the desulfurization process of dibenzothiophene by spectrophotometric techniques. In addition, molecular techniques were used for DNA extraction, BOX-PCR and DNA sequencing in order to obtain a profile of genomic and phylogenetic culturable microbial community present in these samples. Thus, was obtained 50 isolates with the ability to use dibenzothiophene as an energy source, most of which had the form of cocci (68%) with Gram-positive cell wall (44%). After the selection of isolates, by testing Gibb's, obtained a 7 isolates with desulfurization metabolism, and the growth curve, due to the formation of 2-hydroxybiphenyl showed only a strain with high levels of desulfurization, for other strains. The sequencing revealed that the 7 isolates belong to the genus Acinetobacter sp., Pseudomonas sp., and the species Pseudomonas corrugata.
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